CNC milling machine is a kind of automatic processing equipment developed on the basis of general milling machine. Their processing technology is basically the same, and their structure is also similar. CNC milling machines are divided into two categories: without tool magazine and with tool magazine. The CNC milling machine with tool magazine is also called machining center.

In addition to the characteristics of ordinary milling machine, CNC milling has the following characteristics:

1. It has strong adaptability and good flexibility in parts processing, and can process parts with complex contour shape or difficult to control size, such as mold parts, shell parts, etc;

2. It can process parts that can not be processed by ordinary machine tools or are difficult to process, such as complex curve parts described by mathematical models and three-dimensional curved surface parts;

3. It can process the parts that need to be processed by multiple processes after one clamping and positioning;

4. The pulse equivalent of numerical control device is generally 0.001mm, and the high precision numerical control system can reach 0.1 mm μ m. In addition, NC machining also avoids the operator's operation error;

5. High degree of production automation, can reduce the labor intensity of the operator. It is beneficial to the automation of production management;

6. High production efficiency, CNC milling machine generally does not need to use special fixture and other special process equipment, when replacing the workpiece, it only needs to call the processing program, clamping tools and adjust tool data stored in the CNC device, thus greatly shortening the production cycle. Secondly, the CNC milling machine has the functions of milling machine, boring machine and drilling machine, which makes the process highly concentrated and greatly improves the production efficiency. In addition, the spindle speed and feed speed of CNC milling machine are continuously variable, so it is helpful to select the best cutting parameters.