The process of cleaning and roughening metal surfaces using the impact of high-speed sand flow. This method of surface treatment of aluminum parts can achieve a certain degree of cleanliness and different roughness on the surface of the workpiece, improving the mechanical properties of the surface of the workpiece, thus improving the fatigue resistance of the workpiece and increasing the distance between it and the coating. The adhesion extends the durability of the paint film and is also beneficial to the leveling and decoration of the paint.