A fan and a motor thereof are provided. The motor includes a motor drive device. The motor drive device includes a printed circuit board. A control management unit and a voltage converter are arranged on the printed circuit board, the control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed intervals, with each rotation speed interval corresponding to a fixed duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and outputs a pulse width modulation signal having a duty ratio corresponding to the rotation speed interval to which the target rotation speed signal transmitted from the ECU belongs. The voltage converter is connected between the power source and the winding, and is configured to regulate a voltage outputted to the winding in response to the pulse width modulation signal having the fixed duty ratio outputted from the control management unit, to control a rotation speed of the motor. The motor drive device performs segment control on the rotation speed of the motor, thereby reducing the cost.