Sandblasting machine because abrasive to the workpiece surface impact and cutting effect, so that the surface of the workpiece to obtain a certain degree of cleanliness and different roughness, so that the surface of the workpiece improved mechanical properties, thus improving the fatigue resistance of the workpiece, increase the adhesion between it and the coating, prolong the durability of the coating, also conducive to the flow of paint, the surface of the impurity, noise and oxidation layer to remove, while the surface of the media coarsening, eliminating residual stress and improve the substrate surface hardness.