There are many surface treatment technologies for isolation steel pier molds, but the earliest is the surface treatment technology of this mold. It is through surface coating, surface modification or composite treatment technology to change the shape, chemical composition, structure and stress of the mold surface. State, to obtain the required surface performance of the system engineering. At present, nitriding, carburizing and hardened film deposition are mainly used in mold manufacturing. Because the nitriding technology can form a surface with excellent performance, and the nitriding process and the quenching process of the mold steel have good coordination, at the same time, the nitriding temperature is low, and there is no need for intense cooling after nitriding, and the deformation of the mold is minimal, so Surface strengthening is the earlier nitriding technology, and it is also widely used.