Abstract: Aiming at the problems of high difficulty in machining and unsatisfactory machining quality of high-volume-fraction SiCp/Al composites, experimental research on the electrical discharge machining (EDM) process of SiCp/Al composites was carried out. With peak current, pulse width and discharge voltage as input parameters, and material removal rate, tool wear rate and surface roughness as characterization means of EDM machining, orthogonal experiments were designed. The grey relational analysis (GRA) was used to convert multiple process indicators into a comprehensive evaluation indicator, and the optimal combination of main process parameters such as peak current, pulse width and discharge voltage was obtained. The research results show that under the conditions of a peak current of 1.5 A, a pulse width of 60 μs and a discharge voltage of 35 V, the tool wear rate and surface roughness of EDM machining for high-volume-fraction SiCp/Al composites are significantly reduced, and the surface quality is obviously improved.