There is a great demand for hole making of composites in aerospace, in which the defects at exit of holes such as delamination, crack and burr are the main problems at present. In order to suppress the defects at hole exit, a new process of reverse helical milling was proposed. A special tool with special shape was designed and the mechanism of suppressing delamination was also analyzed for the new process. The corresponding schemes were proposed, the feasibility of which was verified by experiments for the hole-making demand of metal/composites laminated structures and composites components. During the experiment, the results were compared and analyzed by recording the process of producing and removing defects. The results show that the reverse helical milling can obviously improve the quality of the hole making by effectively suppressing the formation of the defects of the composites.