During the cutting process of Al-50wt% Si alloy， plastic deformation of aluminum matrix and brittle failure of reinforced silicon particles easily lead to crack， edge collapse， burr and other defects， which is a typical difficult to machine material. In order to solve the problem of poor drilling quality of Al-50wt% Si alloy， this paper adopts single factor experimental method to dry drill Al-50wt% Si alloy， and research on the morphology of hole wall and edge defects. The results show that when the drill feed rate is 0.08 mm/r， the cutting speed increases from 30 m/min to 70 m/min， the axial force increases by 15.8%， and the hole wall surface roughness increases by 19.8%. At lower cutting speeds， the edge appearance at the hole outlet is dominated by particle shedding and burrs. With the increase of cutting speed， the edge appearance at the hole outlet is dominated by matrix ductile fracture，the radial width of edge defect at hole outlet increases； When the drill cutting speed is 50 m/min， the feed rate increases from 0.04 mm/r to 0.12 mm/r， the axial force increases by 74.3% on the whole， and the hole wall surface roughness increases by 50.2%.At lower feed rates increasses，the convex deformation and matrix ductile fracture occur at the outlet side of the hole.As the feed rate， the convex deformation decreases，the radial width of the edge defect at the hole outlet decreases first and then increases，and the minimum radial width is obtained when the feed rate is 0.08 mm/r.