Abstract: In the EDM machining, copper is used as the electrode to process stainless steel (1Cr11Ni2W2MoV) workpieces. In order to reduce the machining time and improve the surface quality of the workpiece, the effects of discharge amplitude, rest amplitude and low voltage current on the surface roughness and machining time of the workpiece are studied. Through the analysis of experimental data, the test results are analyzed in combination with orthogonal experiment and Taguchi algorithm, and the degree of influence of these three elements on it is initially determined, And then use the range analysis method to further process the orthogonal results to obtain the degree of influence of each element on the experiment. It is found that the results of the range analysis are consistent with the conclusions drawn by Taguchi, and the optimal parameter combination is obtained after analysis. Finally, it is verified through experiments that Taguchi method is suitable for EDM.