Metal injection Molding (MIM) is a method to inject metal powder and its binder into the model. It first mixes the selected powder with the binder, then granulates the mixture and then injects it into the desired shape. The polymer entrusts its viscous flow characteristics to the mixture, which contributes to the uniformity of forming, cavity filling and powder filling. After forming, the binder is removed and the debinding billet is sintered. Some sintered products may need further densification, heat treatment or machining. Sintered products not only have the same complex shape and high precision as those produced by plastic injection moulding, but also have similar physical, chemical and mechanical properties to forgings. This technology is suitable for mass production of small, precise, three-dimensional complex shape and metal parts with special performance requirements.