The CNC milling machine is a kind of equipment that can be processed automatically, and it is also a machine with strong processing functions. It also has the functions of a boring machine and a drilling machine, which can make the process highly concentrated and improve the production efficiency. Point control: used for workpiece hole processing, such as center drilling, drilling, reaming, countersinking, reaming, boring and various hole processing operations. Continuous control: through the linear interpolation, arc interpolation, and curve interpolation movement of the CNC milling machine, the plane and curved surface of the workpiece are milled. Tool radius compensation: If you program directly according to the contour of the workpiece, the actual contour will be larger by the tool radius value when processing the inner contour of the workpiece; when the outer contour of the workpiece is processed, the actual contour will be smaller by the cutter radius value. The CNC milling machine can automatically calculate the tool center trajectory, so that the tool center deviates from the contour of the workpiece by a tool radius value, and the contour that meets the requirements of the drawing is processed. Using the tool radius compensation function, changing the tool radius compensation amount can also compensate the tool wear and machining errors, and realize the rough machining and finishing operations of the workpiece. Tool length compensation: changing the tool length compensation amount can compensate the length deviation value after the tool is changed, and also can change the plane position of the cutting process to control the axial positioning accuracy of the tool. Fixed cycle processing: CNC milling machines are using canned cycle processing instructions to simplify processing procedures and reduce programming workload. The CNC milling machine can also be divided into several modules according to the working procedures of the machining process, and subprograms are respectively written, and then called by the main program to complete the processing of the workpiece. This modular program is more convenient for processing and debugging, and optimizes the processing technology.