For the CNC machine tool with open architecture, the detailed analysis of the design of the structural system, the connection between the internal units and the external power supply system on the reliability of the CNC machine tool, and from the power supply processing, grounding and wiring, isolation, Filtering, shielding and other hardware and software design propose a series of anti-interference measures. Reliability is an important indicator to measure the performance of a system. A control system can only perform its various functions under the premise of stable and reliable operation in the long-term. The devices and modules in the system must be strictly controlled to work in coordination. For highly complex and highly automated open CNC machine tools, people are increasingly dependent on them, and their unreliability and insecurity can cause serious damage to themselves and even hurt the operator. The main factor affecting the reliability of CNC machine tools is interference. The reliability of open CNC machine tools is also related to the structural system. The modularization and layering of open architecture and the general software and hardware resources based on PC are the basic guarantees for the reliability of the system. In addition to this, the reliability of the entire architecture can be improved by the following aspects. The open CNC system can significantly improve system reliability by controlling the servo axis, spindle and PLC I / O interface through digital communication interface and communication protocol. System control and diagnostic functions are rich, such as control mode switching and servo parameter setting, which is convenient for system installation and maintenance and has high reliability. The system configuration management module is set up, which enables the system to configure the required numerical control system according to the actual situation, that is, load or unload software modules, provide system default settings and establish connections between modules to improve system reliability. The internal reliability and anti-interference design of CNC machine tools mainly include series system and parallel system according to the logic relationship of each unit of the system. The reliability of the series system is the reliability product of each unit. Obviously, the more the system is connected in series, the longer the chain is, the lower the reliability. In the parallel system, multiple units independently perform the same function, so theoretically, the more units of the parallel system, the higher the reliability. (Finish)