Abstract: Signal composition of the high frequency group pulse,influence of the frequency to the reversed current and the design of the cathode in the high frequency group pulse electrochemical machining(HGPECM) in the processing of ultrathin metal structure parts are discussed.Experiments on processing are carried out.The results indicated that the characteristics of the inter-electrode gap flow field are significantly improved.Electrode passivation is reduced and high quality in machining is obtained.The machining quality is obviously improved with an increase in the main pulse frequency.The dimensional accuracy is reaches up to 30?μm to 40?μm and surface roughness attains 0.30?μm to(0.35?μm.) It is expected that HGPECM can be successfully used in the processing of micro-parts.