diff --git a/IRaCIS.Core.Application/Service/QC/TrialQCQuestionService.cs b/IRaCIS.Core.Application/Service/QC/TrialQCQuestionService.cs
index 702516fb6..44262e01d 100644
--- a/IRaCIS.Core.Application/Service/QC/TrialQCQuestionService.cs
+++ b/IRaCIS.Core.Application/Service/QC/TrialQCQuestionService.cs
@@ -303,7 +303,7 @@ namespace IRaCIS.Core.Application.Contracts
                 }
             }
 
-            var child = await _trialQcQuestionRepository.FirstOrDefaultAsync(x => x.ParentId == addOrEditTrialQCQuestionConfigure.Id);
+            var child = await _trialQcQuestionRepository.FirstOrDefaultAsync(x =>x.ParentId!=null&& x.ParentId == addOrEditTrialQCQuestionConfigure.Id);
             if (child != null && child.ShowOrder < addOrEditTrialQCQuestionConfigure.ShowOrder)
             {
                 //---父问题的显示序号要比子问题的显示序号小，请确认。