diff --git a/Src/Asp.Net/SqlSugar.Access/Access/AccessProvider.cs b/Src/Asp.Net/SqlSugar.Access/Access/AccessProvider.cs
index 18afe7b90..54aacd86c 100644
--- a/Src/Asp.Net/SqlSugar.Access/Access/AccessProvider.cs
+++ b/Src/Asp.Net/SqlSugar.Access/Access/AccessProvider.cs
@@ -142,7 +142,10 @@ namespace SqlSugar.Access
                 if (isTime)
                 {
                     sqlParameter.DbType = System.Data.DbType.String;
-                    sqlParameter.Value = sqlParameter.Value.ToString();
+                    if (sqlParameter.Value != DBNull.Value)
+                    {
+                        sqlParameter.Value = sqlParameter.Value.ToString();
+                    }
                 }
                 if (sqlParameter.Value!=null&& sqlParameter.Value != DBNull.Value && sqlParameter.DbType == System.Data.DbType.DateTime)
                 {