diff --git a/FreeSql/Internal/CommonProvider/InsertOrUpdateProvider.cs b/FreeSql/Internal/CommonProvider/InsertOrUpdateProvider.cs
index 5d97f059..2f309f0b 100644
--- a/FreeSql/Internal/CommonProvider/InsertOrUpdateProvider.cs
+++ b/FreeSql/Internal/CommonProvider/InsertOrUpdateProvider.cs
@@ -127,10 +127,10 @@ namespace FreeSql.Internal.CommonProvider
             {
                 var tempDict = new Dictionary<string, object>();
                 foreach (var item in dicType)
-                { 
+                {
                     foreach (string key in item.Keys)
                     {
-                        if (!tempDict.ContainsKey(key))
+                        if (!tempDict.ContainsKey(key) && !(item[key] is null))
                         {
                             tempDict[key] = item[key];
                         }