CNC machine tools are usually classified from the following different perspectives. 

 1. Classified by process use At present, the variety specifications of CNC machine tools have reached more than 500 kinds, according to their process use can be divided into the following four categories: (1) Metal cutting class It can be divided into two categories: ① Ordinary CNC machine tools ② CNC machining center (2) Metal forming refers to the use of extrusion, pressing, punching, drawing and other forming processes of CNC machine tools, commonly used CNC bending machine, CNC press, CNC punching and shearing machine, CNC bending machine, CNC spinning machine. (3) Special processing mainly includes CNC EDM wire cutting machine, CNC EDM forming machine, CNC laser and flame cutting machine. (4) Measurement and drawing categories mainly include numerical control plotter, numerical control coordinate measuring machine, numerical control cutter and so on. 2. Classified by the mode of control motion (1) Point control CNC machine tools (2) point position linear control CNC machine tools (3) Contour control CNC machine tools 3. Classified according to the control mode of the servo system (1) open loop CNC machine tools. CNC machine tools with open loop control are generally suitable for medium and small economic CNC machine tools. The open-loop control of CNC machine tool is that the input data is calculated by the CNC device to distribute the command pulse, and then the circuit is driven, the stepper motor starts to run, and the machine workbench works. (2) semi-closed loop control CNC machine tools. This kind of control can obtain higher precision than open-loop system, and debugging is more convenient, so it is widely used. The semi-closed loop control machine tool is the input data issued by the numerical control device command value, according to the position of the comparison circuit, select the appropriate speed control circuit, the speed of the servo motor can be fed back to the speed control circuit, and then choose a more appropriate speed to drive the machine table work; The servo motor can compare circuits according to the restart position where the angular displacement feedback is negative. (3) Closed-loop control of CNC machine tools. Closed-loop control CNC machine tool is the input data issued by the CNC device command value, according to the position of the comparison circuit, choose the appropriate speed control circuit, the speed of the servo motor can be fed back to the speed control circuit, and then choose a more appropriate speed, drive the machine table work; The machine table according to the Angle displacement feedback is negative can restart the position comparison circuit selection. Closed-loop control CNC machine tools are generally suitable for CNC machine tools with high precision requirements, such as CNC precision boring and milling machines. 4. Classification according to the grade of the numerical control system used According to the grade of the numerical control system used, the numerical control machine tool is usually divided into low, medium and high-grade three categories. The above medium and high-grade CNC machine tools are generally called full-function CNC or standard CNC.