diff --git a/apps/wpm/serializers.py b/apps/wpm/serializers.py
index b32a27c5..a58acb27 100644
--- a/apps/wpm/serializers.py
+++ b/apps/wpm/serializers.py
@@ -733,6 +733,7 @@ class MlogbInSerializer(CustomModelSerializer):
         elif wm_in.state != WMaterial.WM_OK:
             raise ParseError('非合格品不可使用')
         
+        route = None
         mlog_route = mlog.route
         if mlog_route is None:
             if is_fix is False: