A motor control device includes a rotation speed control circuits a voltage transforming circuit, a buffering circuit and a driving circuit. The rotation speed control circuit provides a rotation speed control signal. The voltage transforming circuit is electrically connected to the rotation speed control circuit and transforms the rotation speed control signal to a speed control voltage signal. The buffering circuit, electrically connected to the voltage transforming circuit, receives the speed control voltage signal and delays or buffers output of the speed control voltage signal. The driving circuit, electrically connected to the buffering circuit, receives the speed control voltage signal from the buffering circuit and generates a driving signal according to the speed control voltage signal so as to control the operation of the motor.