diff --git a/apps/qm/serializers.py b/apps/qm/serializers.py
index 7cffa00a..9a61a73b 100644
--- a/apps/qm/serializers.py
+++ b/apps/qm/serializers.py
@@ -292,6 +292,9 @@ class FtestProcessSerializer(CustomModelSerializer):
                     is_ok = False
                     if not has_is_main:
                         item2["is_main"] = True
+                        has_is_main = True
+                    else:
+                        item2["is_main"] = False
                 FtestDefect.objects.create(ftest=instance, **item2)
             instance.is_ok = is_ok
             instance.save()
@@ -326,7 +329,10 @@ class FtestProcessSerializer(CustomModelSerializer):
                     is_ok = False
                     if not has_is_main:
                         ins.is_main = True
-                        ins.save()
+                        has_is_main = True
+                    else:
+                        ins.is_main = False
+                    ins.save()
             instance.is_ok = is_ok
             instance.save()
         return instance
\ No newline at end of file