To improve the processing quality and efficiency of small tapered holes on the injector of diesel generator, based on existing WEDM machine tools,an integrated EDM drilling and WEDM system was designed. It consisted of microenergy pulse power supply, X,Y,Z threeaxis linkage servo system, wire traveling system, high precision spindle and working fluid circulation system.Each part was designed in detail.The validation test result shows that the system has good feasibility and reliability, can improve product processing quality and efficiency, and has a certain reference value for expanding the application field of EDM technology.