A signal-phase DC motor control circuit is disclosed. The signal-phase DC motor control circuit includes a logic circuit, a switching circuit and a driving circuit. The logic circuit transmits a first logic signal, a second logic signal, a third logic signal and a forth logic signal. The switching circuit transmits a first direction driving signal according to a PWM signal and the first logic signal, and transmits a second direction driving signal according to the PWM signal and the second logic signal. The driving circuit transmits a first output signal according to the first direction driving signal and the fourth logic signal, and transmits a second output signal according to the second direction driving signal and the third logic signal. The first output signal and the second output signal are positive half-wave sinusoidal wave, and the phase difference between the first output signal and the second output signal is 180 degrees.