diff --git a/server/apps/exam/views.py b/server/apps/exam/views.py
index 689d5c0..6a7b8b1 100644
--- a/server/apps/exam/views.py
+++ b/server/apps/exam/views.py
@@ -690,7 +690,7 @@ class ExamRecordViewSet(ListModelMixin, DestroyModelMixin, RetrieveModelMixin, G
                 cer_number = now_data.strftime('%Y%m%d')
                 # 获取锁
                 iden = acquire_lock('certificate')
-                if iden is False:
+                if iden is None:
                     raise ParseError("系统忙， 请稍后再试")
                 try:
                     # 查询证明编号创建时间为最后一个