Based on the Dove Prism scanning principle, a reflective scanning device was designed which was driven by high speed rotating motor and composed of three reflectors in K glyph configuration. The scanning device can be used for the femtosecond laser high-precision spiral drilling system and the accuracy is insensitive to the laser beam quality. The drilling scanning speed is twice as the motor speed with high drilling efficiency. Compared with Dove Prism System, the scanning device is easy to assemble and can avoid the pulse width broadening phenomenon of femtosecond laser. The tests show that it can accomplish high effective drilling the inverted cone micro holes whose diameters are between 0.05 mm and 0.2 mm with the machining accuracy less than ±2 μm.