3D printing in metal industry is mainly used in complex mold processing, complex parts that cannot be completed by traditional processing, aerospace parts processing, military product parts processing, auto parts, hand plate model, artificial limbs, teeth, jewelry design and processing, personalized customization and other fields. Metal industry 3D printer can be quickly formed, no mold, using the product's 3D digital model can be directly printed out the product entity. Compared with the traditional reduced material manufacturing process, the additive manufacturing process can process the complex parts which cannot be processed by the reduced material manufacturing process.