Compared with the ordinary machine tool, CNC machine tool has the following features: (1) the advantages 1. The processing precision is high, has high machining quality. 2. Can be multi-axis linkage, to processing complicated shape parts; 3. The machining parts change, generally only need to change the CNC program, can save production preparation time; 4. The high precision and rigidity of machine tool itself, can choose favorable processing amount, high productivity (generally 3 ~ 5 times of ordinary machine tool). 5. Machine tool automation degree is high, can reduce labor intensity; 6. Mass production, product quality is easy to control; (2) the disadvantages 1. The operator's quality requirement is low, high technical requirements for maintenance personnel. 2. Not easy to control, but its processing route is not like ordinary machine tool directly. 3. The maintenance inconvenience, high technical requirements; 4. The process is not easy to control