diff --git a/apps/qm/serializers.py b/apps/qm/serializers.py
index 006df344..4ae63cfe 100644
--- a/apps/qm/serializers.py
+++ b/apps/qm/serializers.py
@@ -367,24 +367,22 @@ class FtestProcessSerializer(CustomModelSerializer):
         instance = super().create(validated_data)
         for item in ftestitems:
             FtestItem.objects.create(ftest=instance, **item)
+
+        # 判断是否合格和主缺陷
         is_ok = True
         defect_main = None
-        has_is_main = False
         for item2 in ftestdefects:
             defect:Defect = item2["defect"]
             if defect.okcate in [Defect.DEFECT_NOTOK] and item2["has"]:
                 is_ok = False
-                if not has_is_main:
-                    item2["is_main"] = True
-                    has_is_main = True
+                if defect_main is None:
                     defect_main = defect
+                    item2["is_main"] = True
                 else:
                     item2["is_main"] = False
             FtestDefect.objects.create(ftest=instance, **item2)
-        if not is_ok:
-            instance.defect_main = defect_main
-        else:
-            instance.defect_main = None
+            
+        instance.defect_main = defect_main
         instance.is_ok = is_ok
         instance.save()
         return instance
@@ -402,9 +400,8 @@ class FtestProcessSerializer(CustomModelSerializer):
             for k, v in item.items():
                 setattr(ins, k, v)
             ins.save()
-        is_ok = True
-        defect_main = None
-        has_is_main = False
+        
+        # 先保存
         for item2 in ftestdefects:
             try:
                 ins:FtestDefect = FtestDefect.objects.get(ftest=instance, defect=item2["defect"])
@@ -416,22 +413,21 @@ class FtestProcessSerializer(CustomModelSerializer):
             for k, v in item2.items():
                 setattr(ins, k, v)
             ins.save()
-            if ins.is_main:
-                has_is_main = True
-                defect_main = ins.defect
+
+        # 判断是否合格和主缺陷
+        is_ok = True
+        defect_main = None
+        for ins in FtestDefect.objects.filter(ftest=instance).order_by("create_time"):
             if ins.has and ins.defect.okcate in [Defect.DEFECT_NOTOK]:
                 is_ok = False
-                if not has_is_main:
-                    ins.is_main = True
-                    has_is_main = True
+                if defect_main is None:
                     defect_main = ins.defect
+                    ins.is_main = True
                 else:
                     ins.is_main = False
-                ins.save()
-        if not is_ok:
-            instance.defect_main = defect_main
-        else:
-            instance.defect_main = None
+                ins.save(update_fields=["is_main"])
+
+        instance.defect_main = defect_main
         instance.is_ok = is_ok
         instance.save()
         return instance
\ No newline at end of file