(1) after selecting the spraying method, the pretreatment process must be selected, including degreasing, derusting and surface roughening. (2)Spraying: during spraying construction, reasonable process parameters must be determined to control the spraying quality. Including: 1.spraying heat source conditions, that is, the type of fuel and the proportion of mixing with oxygen; 2.Material conveying, that is, the type, speed, flow rate, position and angle of conveying gas; 3. Spraying materials, including material composition, physical properties, powder shape, particle size, wire or bar diameter, etc; 4.Base material composition, base material temperature, performance and surface treatment method of mechanical parts; 5. Spraying operation, including the distance between the spray gun and the parts, the moving speed of the spray gun or parts, the included angle between the spray gun and parts, spraying gas medium, etc. (3)Post coating treatment: sealing treatment or heat treatment shall be carried out immediately after coating. (4) Finish machining: after spraying, the coating needs to be polished to ensure dimensional accuracy. In addition, safety protection must be paid attention to during spraying construction. Including: preventing the harm of high-speed and high-temperature jet to personnel and equipment; Dust prevention and ventilation of spray dust; Safety protection against spray noise and spray arc radiation.