The dry sliding friction wear test of T6 treated Al-10Si-5Cu-0.75Mg alloy was performed with UMT-2 tribometer. The wear mechanisms of the alloy under different load and revolving speed were analyzed by means of SEM, XRD and EDS. The results reveal that the wear rate of Al-10Si-5Cu-0.75Mg alloy is increased with the increase of revolving speed and applied load. but under 800 r/min high revolving speed, Al-10Si-5Cu-0.75Mg alloy still has a good wear resistance. The wear rate of the Al-10Si-5Cu-0.75Mg alloy under 15N applied load is only increase by 291% compared with 5N applied load, this belongs to mild wear. The average friction coefficient changes within the range from 0.35 to 0.40, and the change is small over time, which indicates a strong stability. Meanwhile, as the applied load increases, the wear mechanism is changed from the abrasive wear and the adhesive wear of low applied speed to the delamination wear and the oxidative wear of high applied speed. Keywords: Al-10Si-5Cu-0.75Mg alloy; wear rate; friction coefficient; wear mechanism