Electric discharge machining (EDM) aided tool vibration is an effective method for some certain materials. In the practical machining process, the timely elevation of the tool electrode is needed to eliminate chipping. In this paper, an adaptive fuzzy control system of a servomechanism for EDM combined with ultrasonic vibration is studied. This control system can adjust the discharge pulse parameters timely and the gap between the tool electrode and the workpiece material, therefore, the machining state can be optimal, by which the EDM aided tool ultrasonic vibration is improved and the machining efficiency is increased.