class Program
    {
        static void Main(string[] args)
        {
            GetComList();
        }

        private static void GetComList()
        {try
            {
                using (ManagementObjectSearcher searcher = new ManagementObjectSearcher("select * from Win32_PnPEntity"))
                {
                    Console.WriteLine("本机串口：");

                    var hardInfos = searcher.Get();
                    int index = 1;
                    foreach (var hardInfo in hardInfos)
                    {
                        if (hardInfo.Properties["Name"].Value != null && hardInfo.Properties["Name"].Value.ToString().Contains("(COM"))
                        {
                            String strComName = hardInfo.Properties["Name"].Value.ToString();
                            Console.WriteLine(index + ":" + strComName);//打印串口设备名称及串口号
                            index += 1;
                        }
                    }
                }
                Console.ReadKey();
            }
            catch
            {

            }
        }
    }

效果：

鸣谢
转自：https://www.cnblogs.com/yilinyangyu/p/8405705.html

其他学习资料：

串口通信：https://blog.csdn.net/weixin_45023328/article/details/108128883
串口通信数据格式转换：https://blog.csdn.net/weixin_45023328/article/details/108119294