Copper slag was used to prepare copper powder by way of slurry electrolysis, and the copper powder was used to fabricate copper matrix composite materials reinforced with chemical plating surface modified alumina particulates. Alumina particulates were pretreated in ultrasonic field by chemical copper plating in order to make alumina particulates covered with a layer of copper film and form Al2O3/Cu composite powders. Copper matrix composite materials strengthened with alumina particulates were synthesized by means of pressure molding and sintering. Microstructure of copper matrix composites was researched by means of SEM. SEM analysis shows that alumina particulates distribute in the copper-based body evenly, and combine with copper closely. The effects of sintering temperature, pressure and alumina content on the compactness and hardness of copper matrix composites were studied by orthogonal tests. The compactness of composites increases with the sintering temperature and pressure increasing, and decreases with the alumina content increasing. The hardness of composite materials increases with the sintering temperature, pressure and alumina particulates increasing.