Laser hole machining of carbon fiber reinforced polymer (CFRP) has received a lot of research in recent years. However, most of them are hole cutting machining, and there are few reports on high-quality blind hole machining. In this paper, a femtosecond laser helical drilling device is proposed. It can realize beam deflection and translation through scanning device and a group of lenses respectively, and finally obtain the effect of beam oblique focusing. With beam scanning, the machining taper caused by the focusing characteristics of Gaussian beam can be avoided. Using this device, we studied the 0.3 mm blind hole processing of CFRP, the influence of processing parameters on the machining results and optimization parameters were obtained, and finally a better processing effect of 0.15 mm deep flat bottom straight blind hole was achieved. On this basis, the processing of special-shaped bottom blind hole was further explored. Through layer-by-layer processing, the processing effect of hemispherical blind hole with a section diameter of 0.3 mm is finally obtained. The overall machining quality of the hole is good, and the heat affected zone is less than 5 μm.