diff --git a/Src/Asp.NetCore2/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider_Condition.cs b/Src/Asp.NetCore2/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider_Condition.cs
index ab4b7c587..629dccb6b 100644
--- a/Src/Asp.NetCore2/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider_Condition.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Abstract/SqlBuilderProvider/SqlBuilderProvider_Condition.cs
@@ -373,7 +373,14 @@ namespace SqlSugar
             }
             else
             {
-                inValue1 = ("(" + inArray.Select(it => it == "" ? "null" : it).Distinct().ToArray().ToJoinSqlInVals() + ")");
+                if (item.CSharpTypeName.EqualCase("nstring"))
+                {
+                    inValue1 = ("(" + inArray.Select(it => it == "" ? "null" : it).Distinct().ToArray().ToJoinSqlInValsByVarchar() + ")");
+                }
+                else
+                {
+                    inValue1 = ("(" + inArray.Select(it => it == "" ? "null" : it).Distinct().ToArray().ToJoinSqlInVals() + ")");
+                }
             }
 
             return inValue1;
diff --git a/Src/Asp.NetCore2/SqlSugar/Utilities/DbExtensions.cs b/Src/Asp.NetCore2/SqlSugar/Utilities/DbExtensions.cs
index 00d39e0d2..e148bcb45 100644
--- a/Src/Asp.NetCore2/SqlSugar/Utilities/DbExtensions.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Utilities/DbExtensions.cs
@@ -18,6 +18,17 @@ namespace SqlSugar
                 return string.Join(",", array.Where(c => c != null).Select(it => it.ToSqlValue()));
             }
         }
+        public static string ToJoinSqlInValsByVarchar<T>(this T[] array)
+        {
+            if (array == null || array.Length == 0)
+            {
+                return ToSqlValue(string.Empty);
+            }
+            else
+            {
+                return string.Join(",", array.Where(c => c != null).Select(it => "N"+it.ToSqlValue()));
+            }
+        }
         public static string ToJoinSqlInValsN<T>(this T[] array)
         {
             if (array == null || array.Length == 0)