Shot blasting is to use the high-speed rotating impeller to throw small steel shot or small iron shot to impact the surface of parts at high speed, so that the oxide layer on the surface of parts can be removed. At the same time, steel shot or iron shot impact the surface of parts at high speed, resulting in lattice distortion of parts surface and improving surface hardness. This is a way to clean the surface of parts. Shot peening is often used to clean the surface of aluminum castings or strengthen the surface of parts. In the process of shot blasting, some problems should be paid attention to. First, the dust remover shall be explosion-proof. High concentration of aluminum powder in aluminum casting will cause explosion, so the dust remover must be explosion-proof. Secondly, special steel balls for cleaning aluminum alloy are used. When the steel shot or iron shot hit the surface of the part at high speed, the lattice distortion and the surface hardness of the part increased. After rough polishing, the surface of some aluminum castings is not smooth, which will leave moldy space. Therefore, a fine polishing is used to make the surface smooth.