Has studied the multi-aging Process on a number of low-pressure die-casting of A356 aluminum alloy wheels mechanical properties affected. The results indicated that the multi-ageing alloy the tensile strength, the yield strength, degree of hardness to improve; The elongation ratio drops; And increases the change scope along with the ageing times in the drop, the organizational structure tends to become more stable. A356.2 aluminum alloy grain thickness, after the T6 heat treatment to yield strength and degree of hardness no influence, but the tensile strength and the elongation ratio drop. The research believed that the multi-ageing can cause A356.2 aluminum alloy wheel intensity and hardness enhance, but the ductility drops, and causes the performance to be stabled. In A356.2 aluminum alloy casting process the grain thick its ductility is worse.