Plasma spraying is a material surface strengthening and surface modification technology, which can make the surface of the substrate have the properties of wear resistance, corrosion resistance, high temperature oxidation resistance, electrical insulation, heat insulation, radiation protection, wear reduction and sealing. Plasma spraying technology uses a plasma arc driven by a direct current as a heat source to heat ceramics, alloys, metals and other materials to a molten or semi-molten state, and spray them on the surface of the pretreated workpiece at high speed to form a firm surface layer.