Abstract: In existing EDM equipment, there exist serious problems that the workpiece processed has thin strengthened layer, voids and roughsurface. In order to improve the quality of the strengthened layer, a new type of EDM equipment for surface hardening is devised. It generates 10 kHz charge and discharge pulse by controlling the power devices IGBT. The equipment is fixed with high-frequency stepping torch. In the new equipment, STC12C5204AD sends EXB851 control signal to drive the BSM400GA120DN2. At the same time, a two-phase hybrid stepping motor is driven by controlling constant current chopper integrated driver chip L297, L298. Therefore, pulse randomness defects are overcome. The pulse frequency is significantly increased. Strengthening particles are integrated to generate a larger supporting surface, which connects the strengthening layer. It significantly reduces surface roughness, and greatly strengthens layer thickness.