diff --git a/IRaCIS.Core.Application/Service/ReadingCalculate/PCWG3CalculateService.cs b/IRaCIS.Core.Application/Service/ReadingCalculate/PCWG3CalculateService.cs
index 4b29cd984..5e4264e1e 100644
--- a/IRaCIS.Core.Application/Service/ReadingCalculate/PCWG3CalculateService.cs
+++ b/IRaCIS.Core.Application/Service/ReadingCalculate/PCWG3CalculateService.cs
@@ -102,6 +102,9 @@ namespace IRaCIS.Core.Application.Service.ReadingCalculate
                 taskIds.Add(relatedVisitTask.Item1[count - 1].VisitTaskId);
 
             }
+
+            var baseLineTaskid= relatedVisitTask.Item1[0].VisitTaskId== taskIds[0] ? relatedVisitTask.Item1[0].VisitTaskId: Guid.Empty();
+
             relatedVisitTask.Item1 = relatedVisitTask.Item1.Where(x => taskIds.Contains(x.VisitTaskId)).ToList();
             // 所有访视问题的答案
             var answerList = await _readingTaskQuestionAnswerRepository.Where(x => taskIds.Contains(x.VisitTaskId)).Include(x => x.ReadingQuestionTrial).ToListAsync();
@@ -111,12 +114,21 @@ namespace IRaCIS.Core.Application.Service.ReadingCalculate
 
                 if (item.ReadingQuestionTrial.QuestionType == QuestionType.DaysBetween)
                 {
-                    if (item.Answer == "-1")
+                    if (baseLineTaskid == item.VisitTaskId)
                     {
-                        item.Answer = _localizer["CriterionCalculateExport_Unknown"];
-
-
+                        if (item.Answer == "-1" )
+                        {
+                            item.Answer = "NA";
+                        }
                     }
+                    else
+                    {
+                        if (item.Answer == "-1" || item.Answer == string.Empty)
+                        {
+                            item.Answer = _localizer["CriterionCalculateExport_Unknown"];
+                        }
+                    }
+                   
                 }