diff --git a/Src/Asp.Net/SqlSugar/Abstract/SugarProvider/SqlSugarProvider.cs b/Src/Asp.Net/SqlSugar/Abstract/SugarProvider/SqlSugarProvider.cs
index f9f5f5569..1ca60b783 100644
--- a/Src/Asp.Net/SqlSugar/Abstract/SugarProvider/SqlSugarProvider.cs
+++ b/Src/Asp.Net/SqlSugar/Abstract/SugarProvider/SqlSugarProvider.cs
@@ -520,9 +520,9 @@ namespace SqlSugar
                 string sql = sqlObj.Key;
                 UtilMethods.RepairReplicationParameters(ref sql, sqlObj.Value.ToArray(), i, "UnionAll");
                 if (sqlObj.Value.HasValue())
-                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>($" ( {sql} ) ", sqlObj.Value));
+                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>(GetUnionFomatSql(sql), sqlObj.Value));
                 else
-                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>($" ( {sql} ) ", new List<SugarParameter>()));
+                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>(GetUnionFomatSql(sql), new List<SugarParameter>()));
                 i++;
             }
             var allSql = sqlBuilder.GetUnionAllSql(allItems.Select(it => it.Key).ToList());
@@ -557,9 +557,9 @@ namespace SqlSugar
                 string sql = sqlObj.Key;
                 UtilMethods.RepairReplicationParameters(ref sql, sqlObj.Value.ToArray(), i, "Union");
                 if (sqlObj.Value.HasValue())
-                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>($" ( {sql} ) ", sqlObj.Value));
+                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>(GetUnionFomatSql(sql), sqlObj.Value));
                 else
-                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>($" ( {sql} ) ", new List<SugarParameter>()));
+                    allItems.Add(new KeyValuePair<string, List<SugarParameter>>(GetUnionFomatSql(sql), new List<SugarParameter>()));
                 i++;
             }
             var allSql = sqlBuilder.GetUnionSql(allItems.Select(it => it.Key).ToList());
@@ -580,6 +580,17 @@ namespace SqlSugar
             Check.Exception(queryables.IsNullOrEmpty(), "Union.queryables is null ");
             return Union(queryables.ToArray());
         }
+        private string GetUnionFomatSql(string sql) 
+        {
+            if (this.CurrentConnectionConfig.DbType == DbType.Access)
+            {
+                return sql;
+            }
+            else 
+            {
+                return $" ( {sql} ) ";
+            }
+        }
         #endregion
 
         #region SqlQueryable