Traditional brushless DC motor (BLDCM) drivers which utilize silicon devices, due to the low working frequency and high switch loss, cannot fulfill high-speed applications. Wide-band-gap GaN devices with low turn-on resistance and high switch frequency are the optimum choice for high-speed drivers. A BLDCM driver based on GaN devices is designed. The motor rotation speed of 20 000 r/min is achieved. The BLDCM driver theory is introduced. The GaN devices′ gate-drive resistance is calculated. Choosing gate-drive chip Si8273 to drive GS61008P and using Hall signal to obtain commutation time, the design of high-speed driver is completed. Experiment results show that GaN devices improve the controller′s response significantly and the size of the controller is also comparatively smaller.