In order to process the blade air film holes with small aperture, small taper, no recast layer, micro-cracks and other defects, a femtosecond helical drilling platform was built to carry out the hole drilling test. The working principle of helical drilling optical system was analyzed. The effects of wedge prism deflection angle, mirror translation, hollow motor speed, laser power, and defocusing amount on aperture, taper, splash, and color region of microholes were studied by orthogonal test and variance analysis. It was concluded that in helical drilling the deflection angle of the wedge prism have the most significant effect on the hole diameter and the translation of the reflector had the most significant effect on the taper. The optimized parameters for processing 400 μm cylindrical hole are deflection of the wedge prism 15°, translation of the reflector 15 mm, the hollow motor 2000 r/min, power 16 W, and defocusing 0.2 mm, respectively. This study provides a reference for the selection of parameters in femtosecond helical drilling.