The work aims to optimize electroless copper plating process of α-SiC particles, enhance interfacial wettability and compatibility between α-SiC and Fe, and improve mechanical properties of α-SiC/Fe composites. Besides, it aims to study effects of α-SiC particle size and plating process on copper plating, and effects of copper plating on mechanical properties of α-SiC/Fe composites. After roughening, sensitization and activation of α-SiC particles, α-SiCs with different particle size of 5, 10, 15 and 20 μm were copper-plated by electroless plating. Surface morphology and phase of the coatings were characterized with SEM and XRD. Microstructures of α-SiC/Fe composites were observed with SEM. As a result, the four kinds of α-SiC surfaces were successfully copper-plated. The smaller the particle size was, the larger the surface area and the higher the plating rate were. The optimum process of electroless plating solution was determined as follows: temperature of 65 ℃, solution pH of 9~11, SnCl2 amount of 9 g/L, and PdCl2 amount of 1.5 g/L. Morphology of the coatings was aggregate of rugged copper particles, phases were α-SiC, Cu and a small amount of Cu2O. Electroless plating of α-SiCs with different particle size of 5, 10, 15 and 20 μm improved density, tensile strength and elongation of α-SiC/Fe composites. The density increased by 0.62%, 0.73%, 0.95% and 1.06%, respectively; tensile strength by 5.58%, 10.97%, 11.63% and 13.02%, respectively; and elongation by 6.35%, 12.35%, 10.19% and 10.37%, respectively. Particle size of α-SiC and plating solution process significantly affect plating speed and coating morphology. Copper plating can effectively improve interface defects of α-SiC/Fe composites and enhance mechanical properties.