Abstract:The combined ultrasonic and electrochemical micro-machining technology has many excellences in machining productivity, precision, environmental safety, and also has technical predominance and development potential in aspects of machining micro-structures of cemented carbide. In this paper, the machining mechanism and test device of combined ultrasonic and electrochemical micro-machining is expatiated. Many comparative machining tests of cemented carbide are carried out. The influence of machining parameters such as voltage, feeding force and electrolyte on machining result is analyzed. By optimizing the machining parameters and machining conditions, the micro-machining accuracy of cemented carbide microstructures is increased.