1先添加mongodb -> MongoDB.Driver 驱动

//mongodb 只有数据库->集合-》文档
            // 使用连接字符串连接
            var client = new MongoClient("mongodb://192.168.0.7:27017");

            //获取database
            var mydb = client.GetDatabase("test");
            //获取collection
            var collection = mydb.GetCollection<BsonDocument>("user");

            //待添加的document
            var doc = new BsonDocument{
                        { "_id",3 },
                        { "name", "李四" },
                        { "age", 24 },
                        { "company","冰川"}
                    };
            //InsertOne()添加单条docment
            collection.InsertOne(doc);

具体增删改参考