我的本地和其他服务器用同一段代码都可以访问：

原代码：

RestClient client = new RestClient(url);
client.Timeout = -1;
RestRequest request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer " + access_token);
request.AddHeader("Content-Type", "application/json");
CommanFunction.WriteLog2("UploadData_Error.log", "params2：" + json2);
request.AddParameter("application/json", json2, ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
var text = response.Content;

 返回值是空，statuscode 值是0

原因：

应该是我的本机启用了TLS1.2支持，而服务器上没有启用TLS1.2的支持，所以出现同样的代码本机没问题，而服务器上没法使用。

改后代码：

RestClient client = new RestClient(url);
client.Timeout = -1;
RestRequest request = new RestRequest(Method.POST);--添加的代码
System.Net.ServicePointManager.ServerCertificateValidationCallback += (s, cert, chain, sslPolicyErrors) => true;
System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12 | System.Net.SecurityProtocolType.Tls11 | System.Net.SecurityProtocolType.Tls;--request.AddHeader("Authorization", "Bearer " + access_token);
request.AddHeader("Content-Type", "application/json");
CommanFunction.WriteLog2("UploadData_Error.log", "params2：" + json2);
request.AddParameter("application/json", json2, ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
var text = response.Content;

增加的代码：

System.Net.ServicePointManager.ServerCertificateValidationCallback += (s, cert, chain, sslPolicyErrors) => true;
System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12 | System.Net.SecurityProtocolType.Tls11 | System.Net.SecurityProtocolType.Tls;