Abstract: 7075 aluminum alloy liquid was poured on the surface of 7075-T651 aluminum alloy by impact jet solid-liquid composite casting method, and then the 7075-T651/7075 clad aluminum alloy was obtained. The microstructure, phase composition, hardness distribution, tensile strength and wear resistance of the clad aluminum alloy were investigated. The results show that the clad aluminum alloy was composed of 7075 aluminum alloy covering layer, fusion line and 7075-T651 aluminum alloy substrate, and the substrate was divided into heat affected zone I, heat affected zone Ⅱ and heat affected zone Ⅲ. The covering layer had adendritic structure, the fusion zone consisted of fine equiaxed grains and the heat affected zone was comprised of columnar grains. In the clad aluminum alloy existed phases such as α(Al), η(MgZn₂), η'(MgZn) and T(Al₆CuMg₄). The hardness of the heat-affected zone I was the highest, namely hardening region, and the heat-affected zone Ⅱ was a softening region. The hardness of heat-affected zone Ⅲ was a little lower than that of the original substrate. The higher hardness the region had, the higher wear resistance and tensile strength the region got. The hardness and wear rate of the fusion line were between those of the covering layer and substrate, indicating an excellent metallurgical bonding of the clad aluminum alloy.