diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/DbMaintenance/MongoDbDbMaintenance.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/DbMaintenance/MongoDbDbMaintenance.cs
index 949c23968..5eb337ce1 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/DbMaintenance/MongoDbDbMaintenance.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/DbMaintenance/MongoDbDbMaintenance.cs
@@ -1,4 +1,8 @@
-using System;
+using MongoDb.Ado.data;
+using MongoDB.Bson;
+using MongoDB.Driver;
+using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics.Metrics;
 using System.Linq;
@@ -250,6 +254,13 @@ namespace SqlSugar.MongoDb
         #endregion
 
         #region Methods
+        public override bool TruncateTable(string tableName)
+        {
+            var db =((MongoDbConnection)this.Context.Ado.Connection).GetDatabase();
+             db.GetCollection<BsonDocument>(tableName)
+            .DeleteMany(FilterDefinition<BsonDocument>.Empty);
+            return true;
+        }
         public override List<string> GetIndexList(string tableName)
         {
             var sql = $"SELECT indexname, indexdef FROM pg_indexes WHERE upper(tablename) = upper('{tableName}')";
diff --git a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs
index 85c92dcb5..fa2c33ff7 100644
--- a/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar.MongoDbCore/MongoDb/SqlBuilder/MongoDbQueryBuilder.cs
@@ -86,6 +86,8 @@ namespace SqlSugar.MongoDb
             #region OrderBy
             var order = this.GetOrderByString;
             var orderByString = this.GetOrderByString?.Trim();
+            if (orderByString == "ORDER BY NOW()")
+                orderByString = null;
             if (!string.IsNullOrEmpty(orderByString) && orderByString.StartsWith("ORDER BY ", StringComparison.OrdinalIgnoreCase))
             {
                 order = order.Substring("ORDER BY ".Length).Trim();