diff --git a/EduSystemServer/API/middle.py b/EduSystemServer/API/middle.py
index 209280a..313bd7c 100644
--- a/EduSystemServer/API/middle.py
+++ b/EduSystemServer/API/middle.py
@@ -31,18 +31,18 @@ class JWTMiddleware:
             # 将解码后的 Token 数据存储在 request 中，以便视图可以访问
             if payload.get("type") == "student":
                 if not Student.objects.filter(username=payload.get("username")).exists():
-                    return JsonResponse(ResponseUtil.error("错误信息！"), status=401)
+                    return JsonResponse(ResponseUtil.error("用户不存在！"), status=401)
             if payload.get("type") == "teacher":
                 if not Teacher.objects.filter(username=payload.get("username")).exists():
-                    return JsonResponse(ResponseUtil.error("错误信息！"), status=401)
+                    return JsonResponse(ResponseUtil.error("用户不存在！"), status=401)
             if payload.get("type") == "admin":
                 if not Admin.objects.filter(username=payload.get("username")).exists():
-                    return JsonResponse(ResponseUtil.error("错误信息！"), status=401)
+                    return JsonResponse(ResponseUtil.error("用户不存在！"), status=401)
             request.jwt_payload = payload
         except jwt.ExpiredSignatureError:
-            return JsonResponse(ResponseUtil.error("登录失效！"), status=401)
+            return JsonResponse(ResponseUtil.error("Token 失效，请重新登录！"), status=401)
         except jwt.DecodeError:
-            return JsonResponse(ResponseUtil.error("登录失效！"), status=401)
+            return JsonResponse(ResponseUtil.error("Token Error！"), status=401)
         # 继续处理请求
         response = self.get_response(request)
         return response
\ No newline at end of file
diff --git a/EduSystemServer/API/views.py b/EduSystemServer/API/views.py
index 17abca2..f1dc4e3 100644
--- a/EduSystemServer/API/views.py
+++ b/EduSystemServer/API/views.py
@@ -9,10 +9,13 @@ from teacher.models import Teacher
 from EduSystemServer.settings import TOKEN_KEY
 from EduSystemServer.utils import *
 
+
 # 用户登录成功后生成 JWT Token
 def generate_jwt_token(user, _type):
     # 设置 Token 的有效期
     expiration_time = datetime.utcnow() + timedelta(hours=1)
+    print(datetime.utcnow())
+    print(expiration_time)
 
     # 构建 Token 数据
     payload = {
diff --git a/EduSystemServer/Student/views.py b/EduSystemServer/Student/views.py
index f75a453..9758234 100644
--- a/EduSystemServer/Student/views.py
+++ b/EduSystemServer/Student/views.py
@@ -99,7 +99,7 @@ def select_course(request):
     try:
         request_data = request.POST
         cid = request_data.get("cid")
-        username = request_data.get("username")
+        username = request.jwt_payload.get("username")
         student = Student.objects.filter(username=username).first()
         if SC.objects.filter(cid=cid, sid=student.sid).exists():
             return JsonResponse(ResponseUtil.error("该课程已经选择！"))
diff --git a/EduSystemServer/course/models.py b/EduSystemServer/course/models.py
index fd2466f..455fa36 100644
--- a/EduSystemServer/course/models.py
+++ b/EduSystemServer/course/models.py
@@ -12,15 +12,15 @@ class Course(models.Model):
     credit = models.IntegerField(verbose_name="课程学分", name="credit")
     tid = models.ForeignKey(Teacher, to_field="tid", on_delete=models.CASCADE, name="tid")
 
-    def to_dict(self):
-        return {"cid": self.cid, "c_name": self.name, "type": self.type, "credit": self.credit,
-                "tid": self.tid}
-
     class Meta:
         db_table = "course"
         verbose_name = "课程"
         verbose_name_plural = verbose_name
 
+    def to_dict(self):
+        return {"cid": self.cid, "c_name": self.name, "type": self.type, "credit": self.credit,
+                "tid": self.tid}
+
 
 class SC(models.Model):
     sid = models.ForeignKey(Student, to_field="sid", on_delete=models.CASCADE, name="sid")