diff --git a/apps/inm/services.py b/apps/inm/services.py
index 6865bb0b..dac653d5 100644
--- a/apps/inm/services.py
+++ b/apps/inm/services.py
@@ -63,6 +63,8 @@ class InmService:
             else:
                 raise ParseError('不支持的操作')
             material_count = MaterialBatch.objects.filter(
-                material=material).aggregate(total=Sum('count')).get('total', 0)
+                material=material).aggregate(total=Sum('count'))['total']
+            if material_count is None:
+                material_count = 0
             Material.objects.filter(id=material.id).update(
                 count=material_count)