In order to improve the surfaced mechanical property of 7A52 aluminum alloy, Ai-Si alloy coating was prepared by Supersonic Particles Deposition (SPD) processing on the surface of 7A52 aluminum alloy. The wear-resisting property and wear mechanism of the coating were researched. The results show that the hardness of coating which reached to 266 HV, is similar with that of rolled 7A52 aluminum alloy; the wear weight loss of Ai- Si alloy coating decreased 40%, compared to that of 7A52 aluminum alloy on experimental condition. The dominant wear mechanism of Ai-Si alloy coating is abrasive wear, while the wear mechanism of 7A52 aluminum alloy is micro-cutting together with oxidation-wear.