Craft character of thin-walled parts milling machining was analyzed. According to the deformation error of thin walled parts during peripheral milling processing, peripheral milling experiments for aluminum alloy 6063 were made on vertical machining center by orthogonal experiment method. The influence rules of feeding speed, radial cutting depth and axial cutting depth on machining error of the aluminum alloy were studied. It provides foundation for the reasonable choice of cutting parameters，reducing machining deformation and improving quality of the parts.