In order to solve the problem of the edge defects of SiC_p/Al composites with a volume fraction of 20%, a single factor experiment was carried out to study the influence of cutting parameters on the edge morphology. The results show that the shape of the exit edge is greatly affected by the change of milling speed, and the edges are good at low speed and high speed; when the feed rate is 0.02 and 0.04mm/r, the exit edge are burrs. With the increase of the feed, the edge has serious defects and surface spalling, and then a small number of burrs and defects. When the axial depth of cut is changed, there will be serious defects in the edge of the outlet, and only changing the axial cutting depth has little effect on improving the quality of the edge morphology.