Abstract: Carbon fiber reinforced polymer (CFRP) drive shaft is widely used in lightweight fields such as automobile, aerospace, ship and cooling tower fan because of its excellent performance, but it is prone to burr, delamination and other defects in the drilling process. In order to reveal the formation mechanism of defects in CFRP pipe surface drilling, double point angle drills and candle stick drills were selected to drill CFRP pipe surface. Using the method of drilling blind holes and through holes by some steps, the force of the damaged part was analyzed to study the causes of hole entry tear, hole exit burr and delamination. According to the experimental results, it is found that the hole entry tear of the double point angle drill is large. The tear damage is located at the lowest point of the contact between the drill bit and the pipe surface, and it is mainly the fibers that are horizontally wound around the CFRP pipe. The reason is that the horizontally wound fibers have the largest buckling deformation and are more sensitive to the cutting force. The chisel edge of double point angle drill and candle stick drill had no effect on the final delamination of the hole, and the cutting action of the main cutting edge determined the hole final exit delamination. For using the same drill, the axial force is not the only factor affecting the delamination factor, and the cutting heat should also be considered. Compared with the double point angle drill, the candle stick drill can effectively cut the fiber due to the sharp outer corner edge, making smaller hole exit delamination.