diff --git a/PythonProject/api/grade_api.py b/PythonProject/api/grade_api.py
index c0a33f0..5872b26 100644
--- a/PythonProject/api/grade_api.py
+++ b/PythonProject/api/grade_api.py
@@ -16,6 +16,11 @@ def get_grade(stu_id: int,db=Depends(get_db)):
 
 @gradeAPI.post('/{stu_id}',response_model=GradeResponse,summary='添加学生成绩')
 def post_grade(o:GradeRequest=Form(),db=Depends(get_db)):
+
+    exist_obj = get_grade_dao(db,o.stu_id)
+    if exist_obj:
+        raise HTTPException(status_code=409, detail="该学生此考核序次成绩已存在！")
+
     d=o.model_dump()
     r=add_grade_dao(g=d,db=db)
     if not r: