By using the electric discharge machining and electric chemical machining (EDM/ECM) for cutting processing composite machining method,the processing efficiency and cutting width as the two key indexes to evaluate the composite processing slot, but in the actual machining process,they are often difficult to simultaneously meet the requirements.This experiment using oil in water solution developed, the exploration of technology parameters of electrical discharge machining electrolytic composite by single factor (current, pulse width, pulse interval, electrode plate speed) of influence law on the composite processing effect was made, and through analysis of orthogonal test to the influence of different process parameters of composite machining EDM and ECM, determined the best process parameter combination.Through orthogonal test, considering the processing efficiency and the slit width of the two 〖JP2〗indexes to choose optimal width one（A1B1C3D1）, which determine the process parameters of current 40 A, the pulse interval of 10 μs, the electrode wheel speed 400 r/min, and the pulse width 44 μs for oil in water liquid composite machining as the optimal parameters.