Aiming at the mold pushing pipe of thin-wall parts frequently occured cutting chatter in actual production, assisted by the principle of vibration spectrum analysis, the effects of cutting parameters on vibration were studied by single factor method. The influencing patterns of different cutting speed, cutting depth and feed rate on cutting vibration were drawn. According to the changed patterns, the stable vibration area was determined in which self-excitation chatter was effectively avoided. The optimal cutting processing parameters of thin-wall parts were selected, such as cutting speed 300～350 m/min,cutting depth 0.35 mm and feed speed 0.25 mm/r, which were used to guide the actual production.