With the rapid advancement of science and technology, the mechanical processing industry continues to grow. The rapid prototyping technology, especially laser 3D printing technology, has played an increasingly important role in the mechanical processing industry, and has gradually been widely used in the manufacturing industry, becoming an integral part of today's machinery manufacturing industry. 3D printing technology is rapidly changing our traditional production methods and lifestyles. The 3D printing technology of metal parts as the most advanced and most promising technology in the entire 3D printing system is an important development direction of advanced manufacturing technology. Metal 3D printing technology is divided into three categories according to the addition of metal powders: (1) The laser is used to irradiate the pre-spread metal powder, that is, the metal part is completely covered with the powder after it is molded. This method is currently widely used by equipment manufacturers and research institutes, including direct metal laser sintering (DMLS), selective laser melting (SLM) and LC (LaserCusing); (2) The powder flow delivered by the laser irradiation nozzle is used and the laser is operated simultaneously with the powder (Laser Engineered Net Shaping, LENS). This method is currently used more at home; (3) Electron beam melting of pre-spreading metal powder (Electron Beam Melting, EBM), this method is similar to the first principle, but the use of different heat sources. The selective laser melting technology is an important part of the metal 3D printing field. It adopts a fine focusing spot to quickly melt 300-500 meshes of preset powder materials, and can almost directly obtain functional parts with arbitrary shapes and full metallurgical bonding. Density can reach nearly 100%, size accuracy of 20-50 microns, surface roughness of 20-30 microns, is a promising rapid prototyping technology, and its application has been expanded to aerospace, medical, automotive , molds and other fields. The 3D printing technology of metal parts as the most advanced and most promising technology in the entire 3D printing system is an important development direction of advanced manufacturing technology. SLM equipment generally consists of optical circuit units, mechanical units, control units, process software, and protective gas seal units. Many scientific research institutions and manufacturers at home and abroad have developed more advanced SLM equipment and have mature applications. The development of high-efficiency, cost-effective, large-scale and traditional SLM equipment combined with traditional machining methods is the future direction of metal 3D printing. Huaian Yige New Material Co., Ltd. , https://www.cnygplastic.com