Sand blasting is powered by compressed air. Dalian sand blasting has been processed to form a high-speed jet beam to spray materials (copper ore, quartz sand, carborundum, iron sand and sea sand) to the surface of the workpiece to be treated at high speed, so as to change the appearance or shape of the outer surface of the workpiece surface. Due to the impact and cutting effect of abrasive on the workpiece surface, the surface of the workpiece can obtain certain cleanliness and different roughness, The mechanical properties of the workpiece surface are improved, so the fatigue resistance of the workpiece is improved, the adhesion between it and the coating is increased, the durability of the coating film is prolonged, and it is also conducive to the leveling and decoration of the coating