Permanent magnetic material is a new type of magnetic material, also known as hard magnetic material. The difference between permanent magnetic material and soft magnetic material is that it can maintain constant magnetism after being magnetized under the action of an external magnetic field. Since the third generation of permanent magnet NdFeB came out in the 1980s, it has been favored by people for its cost-effective and abundant resource reserve advantages. The material is in line with the development direction of modern science and technology and information technology towards integration, light weight and intelligence, and effectively promotes the development of modern science and technology and information industry. At present, the material has been widely used in high-tech fields such as computers, network information, aerospace, communications, transportation, home appliances, and health care. However, the current NdFeB permanent magnets still have certain drawbacks in the promotion and application, that is, the NdFeB permanent magnets have poor corrosion resistance, which is caused by its multi-phase structure and the chemical characteristics of each phase. Therefore, solving the anti-corrosion problem of NdFeB has become the focus of current research. The fundamental measure of NdFeB surface protection is to use coating to block the corrosion of oxygen, moisture or other substances in the air to achieve the purpose of protection. After years of research and development, domestic NdFeB permanent magnet material surface protection technology has made great progress, but the anti-corrosion problem of NdFeB permanent magnet material has not been fundamentally solved. The poor sales of domestic NdFeB permanent magnet products are largely due to the failure of the protective coating. Therefore, solving the surface protection problem of NdFeB material is the key to expanding its industrial application. In the future, the focus of research on improving the corrosion resistance of NdFeB is to develop new surface coating processes (such as nano-modified cathodic electrophoretic coating technology) without affecting its magnetic properties to improve the corrosion resistance of the surface of NdFeB permanent magnets; develop new packages Pre-treatment processes such as hole technology; Improve the matching of the combined process of organic coating and metal plating on the surface of NdFeB magnets, so that the corrosion resistance can reach the comprehensive performance of the two.