diff --git a/Src/Asp.Net/SqlSugar/Realization/MySql/DbMaintenance/MySqlDbMaintenance.cs b/Src/Asp.Net/SqlSugar/Realization/MySql/DbMaintenance/MySqlDbMaintenance.cs
index 5b25d2778..9f5e4836e 100644
--- a/Src/Asp.Net/SqlSugar/Realization/MySql/DbMaintenance/MySqlDbMaintenance.cs
+++ b/Src/Asp.Net/SqlSugar/Realization/MySql/DbMaintenance/MySqlDbMaintenance.cs
@@ -185,7 +185,7 @@ namespace SqlSugar
             {
                 foreach (var item in columns)
                 {
-                    if (item.DbColumnName.Equals("GUID",StringComparison.CurrentCultureIgnoreCase))
+                    if (item.DbColumnName.Equals("GUID",StringComparison.CurrentCultureIgnoreCase)&&item.Length==0)
                     {
                         item.Length = 10;
                     }