The structure and implementation method of the remote monitoring and data management system for CNC machine tools based on network technology were introduced.A local machine tool processing monitoring client based on OPC UA communication protocol was designed and developed in C# language,by which the connection between the machine tool OPC UA server and the local monitoring system was realized,and the node data in the server were read and wrote,real-time monitoring to the machine tool internal state data such as machine tool processing parameters,current,voltage and PLC signals was realized by means of subscription.A monitoring database was developed to realize the management of monitoring data.PHP language and ThinkPHP framework were used to build a machine tool remote monitoring website,and users could remotely monitor and manage the internal state data of the machine tool.The software has better openness,can be well connected with the CNC system with OPC UA interface,can better solve the problem of the “information island” of the CNC system,and is practical for improving the intelligence,data visualization and networking of the machine tool.