diff --git a/data_access.py b/data_access.py
new file mode 100644
index 0000000..ae157df
--- /dev/null
+++ b/data_access.py
@@ -0,0 +1,60 @@
+import json
+import os
+from typing import Dict, Any
+
+
+class StudentDataAccess:
+    def __init__(self, file_path: str = 'student_data.json'):
+        self.file_path = file_path
+
+    def load_data(self) -> Dict[str, Any]:
+        """从文件加载所有学生数据"""
+        try:
+            if os.path.exists(self.file_path):
+                with open(self.file_path, 'r', encoding='utf-8') as f:
+                    return json.load(f)
+            return {}
+        except Exception as e:
+            raise Exception(f"加载数据时出错: {e}")
+
+    def save_data(self, data: Dict[str, Any]) -> bool:
+        """保存所有学生数据到文件"""
+        try:
+            with open(self.file_path, 'w', encoding='utf-8') as f:
+                json.dump(data, f, ensure_ascii=False, indent=4)
+            return True
+        except Exception as e:
+            raise Exception(f"保存数据时出错: {e}")
+
+    def get_student(self, student_id: str) -> Dict[str, Any]:
+        """根据学号获取单个学生信息"""
+        data = self.load_data()
+        return data.get(student_id)
+
+    def get_all_students(self) -> Dict[str, Any]:
+        """获取所有学生信息"""
+        return self.load_data()
+
+    def add_student(self, student_id: str, student_info: Dict[str, Any]) -> bool:
+        """添加新学生"""
+        data = self.load_data()
+        if student_id in data:
+            raise Exception("该学号已存在！")
+        data[student_id] = student_info
+        return self.save_data(data)
+
+    def update_student(self, student_id: str, student_info: Dict[str, Any]) -> bool:
+        """更新学生信息"""
+        data = self.load_data()
+        if student_id not in data:
+            raise Exception("该学号不存在！")
+        data[student_id] = student_info
+        return self.save_data(data)
+
+    def delete_student(self, student_id: str) -> bool:
+        """删除学生"""
+        data = self.load_data()
+        if student_id not in data:
+            raise Exception("该学号不存在！")
+        del data[student_id]
+        return self.save_data(data)
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