Thermal diffusion (TD) and vapor physical deposition (PVD) are effective means to strengthen metal surface. The surface hardness of metal can be improved by thermal diffusion (TD) chromizing, but the surface roughness of chromizing layer leads to the phenomenon that the wear rate is too high in the friction process, and the existence of metal elements in thermal diffusion chromizing treatment is not conducive to the surface corrosion resistance. The metal nitride coating prepared by vapor phase physical deposition (PVD) has the characteristics of high hardness, wear resistance and corrosion resistance, which is suitable to be combined with TD chromizing metal layer to form a low friction, wear resistance and corrosion resistance surface. Among them, CrN coating has stable friction coefficient, high wear and corrosion resistance, and is often used as a surface strengthening coating for easily worn parts.