The character and machining principle of Pulse Electrochemical Mechanical Finishing Machining(PECMFM)technology is emphatically studied in this paper. Experiments are made to contrast PECMFM and ECMFM (Eleetrochemical Mechanical Machining),deriving that PECMFM is more efficient and has better surface roughness. This article also analyzes fundamental mechanism of PECMFM.