Abstract:By using the single factor test and orthogonal test method, the cutting experiment of die steel 3Cr2NiMo was carried out on high-speed machining center. By changing cutting parameters affected the machining process, such as: spindle rotate speed, feed rate, axial depth of cut and radical depth of cut, the effects of factor on the workpiece surface roughness levels were studied. The results show that: when increasing the spindle rotate speed of machine tool, roughness values are significantly reduced, but increasing feed rate and axial depth of milling, roughness values are increased. Yet the increased magnitude is different, and the effect of radical depth of milling is not obvious.