Brushless DC motor is composed of motor body and driver, which is a typical mechatronics product. High speed brushless motor refers to the motor without brush and commutator (collector ring), also known as the motor without commutator. Brushless DC motor is widely used in automobiles, tools, industrial control, automation and so on. We also need to know how to use it. Taking ATO's brushless DC motor as an example, this paper describes how to use external switch button to reverse rotation, stop the motor, and external potentiometer to speed the brushless DC motor.