diff --git a/src/main/java/mathlearning/model/User.java b/src/main/java/mathlearning/model/User.java
index 57b7887..6ee96a3 100644
--- a/src/main/java/mathlearning/model/User.java
+++ b/src/main/java/mathlearning/model/User.java
@@ -1,5 +1,7 @@
 package mathlearning.model;
 
+import com.fasterxml.jackson.databind.BeanProperty;
+
 import java.time.LocalDateTime;
 
 public class User {
@@ -9,6 +11,7 @@ public class User {
     private LocalDateTime registrationDate;
     private String verificationCode;
     private boolean verified;
+    private String type;
 
     public User() {}
 
@@ -18,6 +21,7 @@ public class User {
         this.verificationCode = verificationCode;
         this.verified = false;
         this.registrationDate = LocalDateTime.now();
+        this.type = null;
     }
 
     // Getters and setters
@@ -38,4 +42,7 @@ public class User {
 
     public String getUsername() { return  username; }
     public void setUsername(String username) {this.username = username; }
+
+    public String getType() { return type; }
+    public void setType(String type) { this.type = type; }
 }
diff --git a/src/main/java/mathlearning/service/EmailService.java b/src/main/java/mathlearning/service/EmailService.java
index 86f5b0d..cc9dcec 100644
--- a/src/main/java/mathlearning/service/EmailService.java
+++ b/src/main/java/mathlearning/service/EmailService.java
@@ -19,7 +19,7 @@ public class EmailService {
         this.auth = auth;
     }
 
-    public boolean sendVerificationCode(String toEmail, String verificationCode) {
+    public boolean sendVerificationCode(String toEmail, String verificationCode, int flag) {
         try {
             Properties props = new Properties();
             props.put("mail.smtp.host", host);
@@ -38,12 +38,11 @@ public class EmailService {
             message.setFrom(new InternetAddress(username));
             message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(toEmail));
             message.setSubject("数学学习软件 - 注册验证码");
+            String emailContent="";
+
+            if (flag == 1) emailContent = registerContent(verificationCode);
+            else if (flag == 2) emailContent = resetPasswordContent(verificationCode);
 
-            String emailContent = "尊敬的用户：\n\n" +
-                    "您的注册验证码是：" + verificationCode + "\n\n" +
-                    "该验证码有效期为10分钟。\n\n" +
-                    "如果您没有注册本软件，请忽略此邮件。\n\n" +
-                    "数学学习软件团队";
 
             message.setText(emailContent);
 
@@ -54,4 +53,20 @@ public class EmailService {
             return false;
         }
     }
+
+    public String registerContent(String verificationCode) {
+        return "尊敬的用户：\n\n" +
+                "您的注册验证码是：" + verificationCode + "\n\n" +
+                "该验证码有效期为10分钟。\n\n" +
+                "如果您没有注册本软件，请忽略此邮件。\n\n" +
+                "数学学习软件团队";
+    }
+
+    public String resetPasswordContent(String verificationCode) {
+        return "尊敬的用户：\n\n" +
+                "您的重置验证码是：" + verificationCode + "\n\n" +
+                "该验证码有效期为10分钟。\n\n" +
+                "如果您没有重置密码，请忽略此邮件。\n\n" +
+                "数学学习软件团队";
+    }
 }
diff --git a/src/main/java/mathlearning/service/MultipleChoiceGenerator/ComputingUnit.java b/src/main/java/mathlearning/service/MultipleChoiceGenerator/ComputingUnit.java
new file mode 100644
index 0000000..33c4a37
--- /dev/null
+++ b/src/main/java/mathlearning/service/MultipleChoiceGenerator/ComputingUnit.java
@@ -0,0 +1,190 @@
+
+package mathlearning.service.MultipleChoiceGenerator;
+
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Stack;
+
+public class ComputingUnit {
+    String expression;
+    Stack <String> numbers = new Stack<>();
+    Stack <String> operators = new Stack<>();
+
+    ComputingUnit(String Question){
+        expression = Question;
+    }
+
+    private void SplitAndChange(){
+
+        String[] split = expression.split(" ");
+        split = separateParentheses(split);
+        for(int i = 0 ; i < split.length ; i++){
+            if (split[i].charAt(0) == '√') {
+                String StrNum = split[i].substring(1);
+                double num = Math.sqrt(Double.parseDouble(StrNum));
+                split[i] = String.valueOf(num);
+            } else if (split[i].charAt(split[i].length()-1) == '²') {
+                String StrNum = split[i].substring(0, split[i].length()-1);
+                double result = Math.pow(Double.parseDouble(StrNum), 2);
+                split[i] = String.valueOf(result);
+            } else if ((split[i].charAt(0) == 's' || split[i].charAt(0) == 'c'
+                    || split[i].charAt(0) == 't' )) {
+                int index = split[i].indexOf(')');
+                int index2 = split[i].indexOf('(');
+                String StrNum = split[i].substring(index2 + 1, index);
+                double num = Double.parseDouble(SquOrRoot(StrNum));
+                double result = getFunc(split[i].charAt(0), num);
+                split[i] = String.valueOf(result);
+            }
+        }
+        this.expression = String.join(" ", split);
+    }
+
+    public String[] separateParentheses(String[] originalArray) {
+        List<String> result = new ArrayList<>();
+
+        for (String item : originalArray) {
+            if (item.startsWith("(") && item.length() > 1) {
+                // 如果字符串以(开头且长度大于1，分离出(
+                result.add("(");
+                result.add(item.substring(1).trim());
+            } else if (item.endsWith(")") && item.length() > 1 &&
+                    (item.charAt(0) != 's' && item.charAt(0) != 'c' && item.charAt(0) != 't')) {
+                // 如果字符串以)结尾且长度大于1，分离出)
+                result.add(item.substring(0, item.length() - 1).trim());
+                result.add(")");
+            } else if ((item.charAt(0) == 's' || item.charAt(0) == 'c' || item.charAt(0) == 't') &&
+                    (item.endsWith(")") && item.charAt(item.length()-2) == ')')) {
+                result.add(item.substring(0, item.length() - 1).trim());
+                result.add(")");
+            } else {
+                // 其他情况保持不变
+                result.add(item);
+            }
+        }
+
+        return result.toArray(new String[0]);
+    }
+
+
+    private String SquOrRoot(String StrNum){
+        if(StrNum.charAt(0) == '√'){
+            return String.valueOf(Math.sqrt(Double.parseDouble(StrNum.substring(1))));
+        } else if (StrNum.charAt(StrNum.length()-1) == '²') {
+            return String.valueOf(Math.pow(Double.parseDouble(StrNum.substring(0, StrNum.length()-1)), 2));
+        }else {
+            return StrNum;
+        }
+    }
+
+    private double getFunc(char  func, double num){
+        switch (func) {
+            case 's':
+                return Math.sin(num);
+            case 'c':
+                return Math.cos(num);
+            case 't':
+                return Math.tan(num);
+            default:
+                return 0;
+        }
+    }
+
+    private void priority(String operator){
+        if(operators.isEmpty() || operators.peek().equals("(")){
+            operators.push(operator);
+        }else{
+            if((operators.peek().equals("+")|| operators.peek().equals("-")) &&
+                    (operator.equals("×") || operator.equals("÷"))){
+                operators.push(operator);
+            }else{
+                CulAndPushOperator(operator);
+            }
+        }
+    }
+
+    private void CulAndPushOperator(String operator){
+        String num1 = numbers.pop();
+        String num2 = numbers.pop();
+        String operator1 = operators.pop();
+        operators.push(operator);
+        String result = SingleCul(num2, operator1, num1);
+        numbers.push(result);
+    }
+
+    private String Compute(){
+        String[] spilt = expression.split(" ");
+        for (int i = 0; i < spilt.length; i++){
+            if(spilt[i].equals("+") || spilt[i].equals("-") ||
+                    spilt[i].equals("×") || spilt[i].equals("÷") ||
+                    spilt[i].equals("(") ){//处理运算符
+                if( spilt[i].equals("(")){
+                    operators.push(spilt[i]);
+                }else{
+                    priority(spilt[i]);
+                }
+            }else if(spilt[i].equals(")")){
+                String tempResult = numbers.pop();
+                while (!operators.peek().equals("(")){
+                    String operator = operators.pop();
+                    String num1 = numbers.pop();
+                    tempResult = SingleCul(num1, operator, tempResult);
+                }
+                if(operators.peek().equals("(")){
+                    operators.pop();
+                }
+                numbers.push(tempResult);
+            } else {
+                numbers.push(spilt[i]);
+            }
+        }
+        return CulWithoutPriority();
+    }
+
+    private String CulWithoutPriority(){
+        if(numbers.isEmpty()){
+            return "0";
+        }
+        String result = numbers.pop();
+        while (!operators.isEmpty() && !numbers.isEmpty()){
+            String num1 = numbers.pop();
+            String operator = operators.pop();
+            result = SingleCul(num1, operator, result);
+        }
+        return result;
+    }
+
+    public String getAnswer(){
+        SplitAndChange();
+        return Compute();
+    }
+
+    private String SingleCul(String nowResult, String operator, String num){
+        // 使用 trim() 去除首尾空格
+        // 使用 split("\\s+") 按空格分割，只取第一个元素（数字）
+        String cleanNowResult = nowResult.trim().split("\\s+")[0];
+        String cleanNum = num.trim().split("\\s+")[0];
+
+        // 现在可以安全地解析数字了
+        Double result = Double.parseDouble(cleanNowResult);
+        switch (operator) {
+            case "+":
+                result += Double.parseDouble(cleanNum);
+                break;
+            case "-":
+                result -= Double.parseDouble(cleanNum);
+                break;
+            case "×":
+                result *= Double.parseDouble(cleanNum);
+                break;
+            case "÷":
+                result /= Double.parseDouble(cleanNum);
+                break;
+        }
+        return String.valueOf(result);
+    }
+
+
+}
+
diff --git a/src/main/java/mathlearning/service/MultipleChoiceGenerator/MultipleChoiceGenerator.java b/src/main/java/mathlearning/service/MultipleChoiceGenerator/MultipleChoiceGenerator.java
new file mode 100644
index 0000000..bac03e3
--- /dev/null
+++ b/src/main/java/mathlearning/service/MultipleChoiceGenerator/MultipleChoiceGenerator.java
@@ -0,0 +1,92 @@
+package mathlearning.service.MultipleChoiceGenerator;
+import mathlearning.model.User;
+import mathlearning.service.QuestionGenerator.*;
+
+import java.util.*;
+
+public class MultipleChoiceGenerator {
+    private static QuestionGenerator QuestionGenerator = new PrimaryGenerator();
+    String[] QuestionList ;
+    String[] AnswerList   ;
+    String[] ChoiceList   ;
+
+    MultipleChoiceGenerator(int count, User nowUser){// 如此声明MultipleChoiceGenerator实例,再调用下面三个接口
+        this.QuestionList = new String[count];
+        this.ChoiceList   = new String[count];
+        this.QuestionList = SetQuestionList(count, nowUser);
+        SetChoiceList();
+    }
+
+    public String[] GetQuestionList(){
+        return this.QuestionList;
+    }
+
+    public String[] GetChoiceList(){
+        return this.ChoiceList;
+    }
+
+    public String[] GetAnswerList(){
+        return this.AnswerList;
+    }
+
+    private void SetChoiceList(){
+        for(int i = 0 ; i < this.AnswerList.length ; i++){
+            Random random = new Random();
+            String[] choiceNo = {"A.","B.","C.","D."};
+            String[] choices = new String[4];
+            double correctChoice = Double.parseDouble(this.AnswerList[i]);
+            int position = random.nextInt(4);
+            choices[position] = choiceNo[position] +  String.format("%.2f", correctChoice);
+
+
+            for(int j = 0 ; j < 4 ; j++){
+                if(j != position){
+                    double choice = correctChoice;
+                    double offset = random.nextInt(41) - 20;
+                    choice += offset;
+                    choices[j] =choiceNo[j] + String.format("%.2f", choice);
+                }
+            }
+
+            this.ChoiceList[i] = String.join("\n", choices);
+        }
+    }
+
+    private String[] SetQuestionList(int count, User nowUser){
+        String[] Questions= new String[count];
+        if(nowUser.getType().equals("小学") ) {
+            QuestionGenerator = new PrimaryGenerator();
+        }
+        else if( nowUser.getType().equals("初中") ) {
+            QuestionGenerator = new middleGenerator();
+        }
+        else if( nowUser.getType().equals("高中") ) {
+            QuestionGenerator = new highGenerator();
+        }
+
+        List<String> questions = new ArrayList<>();
+        Set<String> generatedQuestions = new HashSet<>();
+
+        for (int i = 0; i < count; i++) {
+            String question;
+            do {
+                question =  QuestionGenerator.generateQuestion();
+            } while ( generatedQuestions.contains(question ));
+            generatedQuestions.add(question);
+            questions.add(question);
+        }
+
+        for(int i = 0 ; i< count ; i++){
+            Questions[i] = questions.get(i);
+        }
+        this.AnswerList = new String[count];
+        for(int i = 0 ; i< count ; i++){
+            ComputingUnit computingUnit = new ComputingUnit(Questions[i]);
+            this.AnswerList[i] = computingUnit.getAnswer();
+        }
+        return Questions;
+    }
+
+
+
+}
diff --git a/src/main/java/mathlearning/service/MultipleChoiceGenerator/MultipleChoiceGeneratorTest.java b/src/main/java/mathlearning/service/MultipleChoiceGenerator/MultipleChoiceGeneratorTest.java
new file mode 100644
index 0000000..260dd42
--- /dev/null
+++ b/src/main/java/mathlearning/service/MultipleChoiceGenerator/MultipleChoiceGeneratorTest.java
@@ -0,0 +1,37 @@
+package mathlearning.service.MultipleChoiceGenerator;
+
+import mathlearning.model.User;
+
+public class MultipleChoiceGeneratorTest {
+    public static void main(String[] args) {
+        // 创建一个模拟用户
+        User testUser = new User();
+        testUser.setType("小学"); // 可以分别测试"小学"、"初中"、"高中"
+
+        // 测试生成10道题目
+        int questionCount = 10;
+        MultipleChoiceGenerator generator = new MultipleChoiceGenerator(questionCount, testUser);
+
+        // 获取生成的题目、答案和选项
+        String[] questions = generator.GetQuestionList();
+        String[] answers = generator.GetAnswerList();
+        String[] choices = generator.GetChoiceList();
+
+        // 输出测试结果
+        System.out.println("=== 数学题目生成测试 ===");
+        System.out.println("用户类型: " + testUser.getType());
+        System.out.println("生成题目数量: " + questionCount);
+        System.out.println();
+
+        for (int i = 0; i < questions.length; i++) {
+            System.out.println("题目 " + (i + 1) + ": " + questions[i]);
+            System.out.println("答案: " + answers[i]);
+            System.out.println("选项:");
+            String[] choiceArray = choices[i].split("\n");
+            for (int j = 0; j < choiceArray.length; j++) {
+                System.out.println("  " + (char)('A' + j) + ". " + choiceArray[j]);
+            }
+            System.out.println("----------------------------------------");
+        }
+    }
+}
diff --git a/src/main/java/mathlearning/service/QuestionGenerator/PrimaryGenerator.java b/src/main/java/mathlearning/service/QuestionGenerator/PrimaryGenerator.java
new file mode 100644
index 0000000..d4f73fc
--- /dev/null
+++ b/src/main/java/mathlearning/service/QuestionGenerator/PrimaryGenerator.java
@@ -0,0 +1,22 @@
+package mathlearning.service.QuestionGenerator;
+
+public class PrimaryGenerator extends  QuestionGenerator{
+    public PrimaryGenerator() {
+        super("小学");
+    }
+
+    @Override
+    public String generateQuestion() {
+
+        int operandCount = random.nextInt(4) + 2;
+
+        // 生成操作数
+        int[] operands = new int[operandCount];
+        for (int i = 0; i < operandCount; i++) {
+            operands[i] = random.nextInt(100) + 1; // 1-100
+        }
+
+        String question =  preForOper(operands);
+        return addParen(question);
+    }
+}
diff --git a/src/main/java/mathlearning/service/QuestionGenerator/QuestionGenerator.java b/src/main/java/mathlearning/service/QuestionGenerator/QuestionGenerator.java
new file mode 100644
index 0000000..b41d315
--- /dev/null
+++ b/src/main/java/mathlearning/service/QuestionGenerator/QuestionGenerator.java
@@ -0,0 +1,142 @@
+package mathlearning.service.QuestionGenerator;
+
+import java.util.Random;
+
+public abstract class   QuestionGenerator{
+    protected Random random = new Random();
+    public abstract String generateQuestion() ;
+    protected String type;
+
+    public String getType() {
+        return type;
+    }
+
+    QuestionGenerator() {
+        type = "无";
+    }
+
+    QuestionGenerator(String Type) {
+        type = Type;
+    }
+
+    protected String  preForOper(int[] operands) {
+        StringBuilder question = new StringBuilder();
+        String[] operators = {"+", "-", "×", "÷"};
+        question.append(operands[0]);
+
+        for (int i = 1; i < operands.length; i++) {
+            String op = operators[ random.nextInt (operators.length)];
+            question.append(" ").append(op).append(" ").append(operands[i]);
+        }
+        return question.toString();
+
+    }
+
+    protected boolean Check_num(String expression) {
+        if(!(expression.equals("+") || expression.equals("-") || expression.equals("×") || expression.equals("÷"))) {
+            return true;
+        }
+        else{
+            return  false;
+        }
+    }
+
+    protected String addParen(String expression) {
+        String[] parts = expression.split(" ");
+        StringBuilder result = new StringBuilder();
+        boolean r_paren_needed = false;
+
+        for (int i = 0; i < parts.length; i++) {
+            if(Check_num ( parts [i]) ) {
+                if( !r_paren_needed ) {
+                    if(i <= parts.length -3 )
+                    {
+                        if( random.nextBoolean() )
+                        { result.append("(");r_paren_needed = true;}
+                    }
+                    result.append(parts[i]);
+                } else {
+                    result.append( parts [i]);
+                    if( !random.nextBoolean()) {
+                        result.append(")");r_paren_needed = false;
+                    }
+                }
+            } else {
+                result.append( parts [i] );
+            }
+            if( i < parts.length -1 ) {
+                result.append(" ");
+            }
+        }
+
+        if( r_paren_needed ){
+            result.append(")");r_paren_needed = false;
+        }
+        return result.toString();
+    }
+
+    protected String add_squs(String expression) {
+        String[] parts = expression.split(" ");
+        StringBuilder result = new StringBuilder();
+        boolean has_squs = false;
+
+        for (int i = 0; i < parts.length; i++) {
+            if( Check_num( parts [i] )) {
+                double Thres = 0.3;
+                if( !has_squs){
+                    Thres = 0.7;
+                }
+                if ( random.nextDouble() < Thres ||(i == parts.length -1 && !has_squs)) {
+                    if ( random.nextBoolean() ) {
+                        result.append(parts[i]);
+                        result.append("²");
+                        has_squs = true;
+                    } else {
+                        result.append("√");
+                        result.append(parts[i]);
+                        has_squs = true;
+                    }
+                } else {
+                    result.append(parts[i]);
+                }
+            } else {
+                result.append(parts[i]);
+            }
+            if( i < parts.length -1 ) {
+                result.append(" ");
+            }
+        }
+        return result.toString();
+    }
+
+    protected String add_sins(String expression) {
+        String[] parts = expression.split(" ");
+        StringBuilder result = new StringBuilder();
+        String[] functions = {"sin", "cos", "tan"};
+        boolean has_func = false;
+
+        for (int i = 0; i < parts.length; i++) {
+            double Thres = 0.4;
+            if(!has_func){Thres = 0.8;}
+            if(Check_num(parts[i]))
+            {
+                if ( random.nextDouble() < Thres ||(i == parts.length-1 && !has_func) ) {
+                    String func = functions[random.nextInt(functions.length)];
+                    result.append(func).append("(").append(parts[i]).append(")");
+                } else {
+                    result.append(parts[i]);
+                }
+            } else {
+                result.append(parts[i]);
+            }
+            if( i < parts.length-1 ) {
+                result.append(" ");
+            }
+
+        }
+
+        return result.toString();
+    }
+}
+
+
diff --git a/src/main/java/mathlearning/service/QuestionGenerator/highGenerator.java b/src/main/java/mathlearning/service/QuestionGenerator/highGenerator.java
new file mode 100644
index 0000000..bfc17fc
--- /dev/null
+++ b/src/main/java/mathlearning/service/QuestionGenerator/highGenerator.java
@@ -0,0 +1,24 @@
+package mathlearning.service.QuestionGenerator;
+
+public class highGenerator extends  QuestionGenerator{
+
+    public highGenerator() {
+        super("高中");
+    }
+
+    @Override
+    public String generateQuestion() {
+        int operandCount = random.nextInt(4) + 2;
+
+        // 生成操作数
+        int[] operands = new int[ operandCount ];
+        for (int i = 0; i < operandCount; i++) {
+            operands[i] = random.nextInt(100) + 1; // 1-100
+        }
+
+        String question =  preForOper( operands );
+        question = add_squs( question );
+        question = add_sins( question );
+        return addParen( question );
+    }
+}
diff --git a/src/main/java/mathlearning/service/QuestionGenerator/middleGenerator.java b/src/main/java/mathlearning/service/QuestionGenerator/middleGenerator.java
new file mode 100644
index 0000000..b1d3b61
--- /dev/null
+++ b/src/main/java/mathlearning/service/QuestionGenerator/middleGenerator.java
@@ -0,0 +1,23 @@
+package mathlearning.service.QuestionGenerator;
+
+public class middleGenerator extends  QuestionGenerator{
+
+    public middleGenerator() {
+        super("初中");
+    }
+
+    @Override
+    public String generateQuestion() {
+        int operandCount = random.nextInt(4) + 2;
+
+        // 生成操作数
+        int[] operands = new int [ operandCount ];
+        for (int i = 0; i < operandCount; i++) {
+            operands[i] = random.nextInt(100) + 1; // 1-100
+        }
+
+        String question =  preForOper(operands);
+        question = add_squs(question);
+        return addParen(question);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/mathlearning/service/UserService.java b/src/main/java/mathlearning/service/UserService.java
index f239562..f9c0c95 100644
--- a/src/main/java/mathlearning/service/UserService.java
+++ b/src/main/java/mathlearning/service/UserService.java
@@ -147,6 +147,58 @@ public class UserService {
         return true;
     }
 
+    public boolean setPasswordResetCode(String email, String verificationCode) {
+        User user = users.get(email);
+        if (user == null) {
+            return false; // 用户不存在
+        }
+
+        user.setVerificationCode(verificationCode);
+        verificationCodeTimestamps.put(email, LocalDateTime.now());
+        saveUsers();
+        return true;
+    }
+
+    public boolean resetPasswordWithCode(String email, String verificationCode, String newPassword) {
+        User user = users.get(email);
+        if (user == null) {
+            return false;
+        }
+
+        // 验证验证码
+        if (!user.getVerificationCode().equals(verificationCode)) {
+            return false;
+        }
+
+        // 检查验证码是否过期
+        LocalDateTime codeTime = verificationCodeTimestamps.get(email);
+        if (codeTime == null || codeTime.plusMinutes(VERIFICATION_CODE_EXPIRY_MINUTES).isBefore(LocalDateTime.now())) {
+            return false;
+        }
+
+        // 验证新密码格式
+        if (!validatePassword(newPassword)) {
+            return false;
+        }
+
+        // 更新密码
+        String newPasswordHash = BCrypt.withDefaults().hashToString(12, newPassword.toCharArray());
+        user.setPasswordHash(newPasswordHash);
+        verificationCodeTimestamps.remove(email); // 清除验证码
+        saveUsers();
+        return true;
+    }
+
+    public boolean updateUserType(String email, String type) {
+        User user = users.get(email);
+        if (user == null) {
+            return false;
+        }
+        user.setType(type);
+        saveUsers();
+        return true;
+    }
+
     public boolean validatePassword(String password) {
         if (password.length() < 6 || password.length() > 10) {
             return false;
@@ -169,7 +221,17 @@ public class UserService {
         return users.containsKey(email);
     }
 
+    public boolean isUserExistsAndVerified(String email) {
+        User user = users.get(email);
+        return user != null && user.isVerified();
+    }
+
     public boolean isValidEmail(String email) {
         return email.matches("^[A-Za-z0-9+_.-]+@(.+)$");
     }
+
+    public User getUser(String email ) {
+        User user = users.get(email);
+        return user;
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/mathlearning/ui/ChangeCodeFrame.java b/src/main/java/mathlearning/ui/ChangeCodeFrame.java
new file mode 100644
index 0000000..1255136
--- /dev/null
+++ b/src/main/java/mathlearning/ui/ChangeCodeFrame.java
@@ -0,0 +1,221 @@
+package mathlearning.ui;
+
+import mathlearning.service.EmailService;
+import mathlearning.service.UserService;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class ChangeCodeFrame extends JFrame {
+    private UserService userService;
+    private EmailService emailService;
+    private LoginFrame loginFrame;
+
+    private JTextField emailField;
+    private JButton sendCodeButton;
+    private JTextField codeField;
+    private JPasswordField passwordField;
+    private JPasswordField confirmPasswordField;
+    private JButton registerButton;
+    private JButton backButton;
+
+    private String verificationCode;
+
+    public ChangeCodeFrame(UserService userService, LoginFrame loginFrame) {
+        this.userService = userService;
+        this.loginFrame = loginFrame;
+
+        // 配置邮箱服务（需要替换为真实的邮箱配置）
+        this.emailService = new EmailService(
+                "smtp.qq.com",
+                "587",
+                "2793415226@qq.com",  // 替换为你的QQ邮箱
+                "rmiomlakglpjddhb",  // 替换为你的授权码
+                true
+        );
+
+        initializeUI();
+    }
+
+    private void initializeUI() {
+        setTitle("数学学习软件 - 忘记密码");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(450, 400);
+        setLocationRelativeTo(null);
+        setResizable(false);
+
+        // 主面板
+        JPanel mainPanel = new JPanel(new BorderLayout(10, 10));
+        mainPanel.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
+
+        // 标题
+        JLabel titleLabel = new JLabel("重置密码", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 24));
+        mainPanel.add(titleLabel, BorderLayout.NORTH);
+
+        //表单面板
+        JPanel formPanel = new JPanel(new GridLayout(5, 2, 10, 10));
+
+        JLabel emailLabel = new JLabel("邮箱:");
+        emailLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        emailField = new JTextField();
+
+        JLabel codeLabel = new JLabel("验证码:");
+        codeLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+
+        JPanel codePanel = new JPanel(new BorderLayout());
+        codeField = new JTextField();
+        sendCodeButton = new JButton("发送验证码");
+        sendCodeButton.addActionListener(new SendCodeListener());
+
+        codePanel.add(codeField, BorderLayout.CENTER);
+        codePanel.add(sendCodeButton, BorderLayout.EAST);
+
+        JLabel passwordLabel = new JLabel("新密码:");
+        passwordLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        passwordField = new JPasswordField();
+
+        JLabel confirmPasswordLabel = new JLabel("确认密码:");
+        confirmPasswordLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        confirmPasswordField = new JPasswordField();
+
+        formPanel.add(emailLabel);
+        formPanel.add(emailField);
+        formPanel.add(codeLabel);
+        formPanel.add(codePanel);
+        formPanel.add(passwordLabel);
+        formPanel.add(passwordField);
+        formPanel.add(confirmPasswordLabel);
+        formPanel.add(confirmPasswordField);
+
+        mainPanel.add(formPanel, BorderLayout.CENTER);
+
+        // 按钮面板
+        JPanel buttonPanel = new JPanel(new FlowLayout());
+
+        registerButton = new JButton("更改密码");
+        registerButton.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        registerButton.addActionListener(new ChangeCodeFrame.ChangeCodeButtonListener());
+
+        backButton = new JButton("返回登录");
+        backButton.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        backButton.addActionListener(e -> goBackToLogin());
+
+        buttonPanel.add(registerButton);
+        buttonPanel.add(backButton);
+
+        mainPanel.add(buttonPanel, BorderLayout.SOUTH);
+
+        add(mainPanel);
+    }
+
+    private class SendCodeListener implements ActionListener {
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            String email = emailField.getText().trim();
+
+            if (email.isEmpty()) {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "请输入邮箱地址", "错误", JOptionPane.ERROR_MESSAGE);
+                return;
+            }
+
+            if (!userService.isValidEmail(email)) {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "邮箱格式不正确", "错误", JOptionPane.ERROR_MESSAGE);
+                return;
+            }
+
+            // 检查用户是否存在且已验证
+            if (!userService.isUserExistsAndVerified(email)) {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "该邮箱未注册或未验证", "错误", JOptionPane.ERROR_MESSAGE);
+                return;
+            }
+
+            // 生成6位验证码
+            verificationCode = String.valueOf((int)((Math.random() * 9 + 1) * 100000));
+
+            // 发送验证码邮件
+            boolean sent = emailService.sendVerificationCode(email, verificationCode, 2);
+
+            if (sent) {
+                // 在服务中保存验证码
+                boolean codeSaved = userService.setPasswordResetCode(email, verificationCode);
+
+                if (codeSaved) {
+                    JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                            "验证码已发送到您的邮箱，请查收", "成功", JOptionPane.INFORMATION_MESSAGE);
+
+                    // 禁用发送按钮60秒
+                    sendCodeButton.setEnabled(false);
+                    new Thread(() -> {
+                        try {
+                            for (int i = 60; i > 0; i--) {
+                                final int current = i;
+                                SwingUtilities.invokeLater(() ->
+                                        sendCodeButton.setText(current + "秒后重发"));
+                                Thread.sleep(1000);
+                            }
+                            SwingUtilities.invokeLater(() -> {
+                                sendCodeButton.setText("发送验证码");
+                                sendCodeButton.setEnabled(true);
+                            });
+                        } catch (InterruptedException ex) {
+                            ex.printStackTrace();
+                        }
+                    }).start();
+                } else {
+                    JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                            "保存验证码失败", "错误", JOptionPane.ERROR_MESSAGE);
+                }
+            } else {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "验证码发送失败，请检查邮箱地址或网络连接", "错误", JOptionPane.ERROR_MESSAGE);
+            }
+        }
+    }
+
+    private class ChangeCodeButtonListener implements ActionListener {
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            String email = emailField.getText().trim();
+            String code = codeField.getText().trim();
+            String password = new String(passwordField.getPassword());
+            String confirmPassword = new String(confirmPasswordField.getPassword());
+
+            // 验证输入
+            if (email.isEmpty() || code.isEmpty() || password.isEmpty()) {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "请填写所有字段", "错误", JOptionPane.ERROR_MESSAGE);
+                return;
+            }
+            if (!password.equals(confirmPassword)) {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "两次输入的密码不一致", "错误", JOptionPane.ERROR_MESSAGE);
+                return;
+            }
+            if (!userService.validatePassword(password)) {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "密码必须为6-10位，且包含大小写字母和数字", "错误", JOptionPane.ERROR_MESSAGE);
+                return;
+            }
+
+            if (userService.resetPasswordWithCode(email, code, password)) {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "密码重置成功!", "成功", JOptionPane.INFORMATION_MESSAGE);
+                goBackToLogin();
+            } else {
+                JOptionPane.showMessageDialog(ChangeCodeFrame.this,
+                        "重置失败，请检查验证码是否正确或是否已过期", "错误", JOptionPane.ERROR_MESSAGE);
+            }
+        }
+    }
+
+    private void goBackToLogin() {
+        loginFrame.setVisible(true);
+        this.dispose();
+    }
+}
diff --git a/src/main/java/mathlearning/ui/LoginFrame.java b/src/main/java/mathlearning/ui/LoginFrame.java
index a9579d0..b6d00b0 100644
--- a/src/main/java/mathlearning/ui/LoginFrame.java
+++ b/src/main/java/mathlearning/ui/LoginFrame.java
@@ -63,8 +63,13 @@ public class LoginFrame extends JFrame{
         registerButton.setFont(new Font("微软雅黑", Font.PLAIN, 14));
         registerButton.addActionListener(e -> openRegisterFrame());
 
+        JButton changeCodeButton = new JButton("忘记密码？");
+        changeCodeButton.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        changeCodeButton.addActionListener(e -> openChangeCodeFrame());
+
         buttonPanel.add(loginButton);
         buttonPanel.add(registerButton);
+        buttonPanel.add(changeCodeButton);
 
         mainPanel.add(buttonPanel, BorderLayout.SOUTH);
 
@@ -101,11 +106,57 @@ public class LoginFrame extends JFrame{
         this.setVisible(false);
     }
 
+    private void openChangeCodeFrame() {
+        ChangeCodeFrame changeCodeFrame = new ChangeCodeFrame(userService, this);
+        changeCodeFrame.setVisible(true);
+        this.setVisible(false);
+    }
+
     private void openMainFrame(String email) {
+        User user = userService.getUser(email);
+        // 如果用户类型为空，让用户选择类型
+        if (user.getType() == null || user.getType().isEmpty()) {
+            String[] types = {"小学", "初中", "高中"};
+            String selectedType = (String) JOptionPane.showInputDialog(
+                    this,
+                    "欢迎 " + user.getUsername() + "!\n请选择您的教育阶段：",
+                    "选择教育阶段",
+                    JOptionPane.QUESTION_MESSAGE,
+                    null,
+                    types,
+                    types[0] // 默认选择第一个
+            );
+
+            // 如果用户选择了类型（没有点击取消）
+            if (selectedType != null) {
+                // 更新用户类型
+                boolean updated = userService.updateUserType(email, selectedType);
+                if (updated) {
+                    // 更新本地user对象
+                    user.setType(selectedType);
+                    JOptionPane.showMessageDialog(this,
+                            "登录成功！\n教育阶段：" + selectedType,
+                            "登录成功", JOptionPane.INFORMATION_MESSAGE);
+                } else {
+                    JOptionPane.showMessageDialog(this,
+                            "登录成功！\n但教育阶段设置失败",
+                            "登录成功", JOptionPane.WARNING_MESSAGE);
+                }
+            } else {
+                // 如果用户取消选择，可以设置默认类型或者保持为空
+                userService.updateUserType(email, "小学");
+                user.setType("小学");
+                JOptionPane.showMessageDialog(this,
+                        "登录成功！\n已为您选择默认教育阶段：小学",
+                        "登录成功", JOptionPane.INFORMATION_MESSAGE);
+            }
+        } else {
+            // 如果已经有类型，直接显示欢迎信息
+            JOptionPane.showMessageDialog(this,
+                    "欢迎 " + user.getUsername() + "!\n登录成功。\n教育阶段：" + user.getType(),
+                    "登录成功", JOptionPane.INFORMATION_MESSAGE);
+        }
 
-        // 这里先简单显示一个消息，后续可以扩展为主界面
-        JOptionPane.showMessageDialog(this,
-                "欢迎 " + email + "!\n登录成功，主界面功能待实现。",
-                "登录成功", JOptionPane.INFORMATION_MESSAGE);
+        // openMainApplicationWindow(user);
     }
 }
diff --git a/src/main/java/mathlearning/ui/MainFrame.java b/src/main/java/mathlearning/ui/MainFrame.java
new file mode 100644
index 0000000..abf8743
--- /dev/null
+++ b/src/main/java/mathlearning/ui/MainFrame.java
@@ -0,0 +1,53 @@
+package mathlearning.ui;
+
+import mathlearning.model.User;
+import mathlearning.service.UserService;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class MainFrame extends JFrame {
+    private User currentUser;
+    private UserService userService;
+    private JLabel welcomeLabel;
+
+    public MainFrame(User user, UserService userService) {
+        this.currentUser = user;
+        this.userService = userService;
+        InitializeUI();
+    }
+
+    private void InitializeUI() {
+        setTitle("数学学习软件 - 菜单");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(500, 400);
+        setLocationRelativeTo(null);
+        setResizable(false);
+
+        // 主面板
+        JPanel titlePanel = new JPanel(new BorderLayout());
+        JPanel mainPanel = new JPanel(new BorderLayout(10, 10));
+        mainPanel.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
+
+        // 欢迎用户与type信息
+        welcomeLabel = new JLabel("欢迎"+currentUser.getUsername()+"!", JLabel.CENTER);
+        welcomeLabel.setFont(new Font("微软雅黑", Font.BOLD, 24));
+
+        JLabel typeLabel = new JLabel("当前选择的测试题为" + currentUser.getType() + "难度", JLabel.CENTER);
+        typeLabel.setFont(new Font("微软雅黑", Font.BOLD, 16));
+        typeLabel.setForeground(Color.BLUE);
+
+        titlePanel.add(welcomeLabel, BorderLayout.NORTH);
+        titlePanel.add(typeLabel, BorderLayout.CENTER);
+        mainPanel.add(titlePanel, BorderLayout.NORTH);
+
+        // 功能按钮区域
+        JPanel centerButtonPanel = new JPanel(new GridLayout(2, 1, 15, 15));
+        centerButtonPanel.setBorder(BorderFactory.createEmptyBorder(30, 50, 30, 50));
+
+
+
+    }
+}
diff --git a/src/main/java/mathlearning/ui/RegisterFrame.java b/src/main/java/mathlearning/ui/RegisterFrame.java
index ebc97c7..b5fc993 100644
--- a/src/main/java/mathlearning/ui/RegisterFrame.java
+++ b/src/main/java/mathlearning/ui/RegisterFrame.java
@@ -145,7 +145,7 @@ public class RegisterFrame extends JFrame{
             verificationCode = String.valueOf((int)((Math.random() * 9 + 1) * 100000));
 
             // 发送验证码邮件
-            boolean sent = emailService.sendVerificationCode(email, verificationCode);
+            boolean sent = emailService.sendVerificationCode(email, verificationCode, 1);
 
             if (sent) {
                 JOptionPane.showMessageDialog(RegisterFrame.this,