A switching power supply circuit is disclosed in an embodiment. The switching power supply circuit includes a power output stage, a pulse width modulation (PWM) signal generator, a compensation module, and a overshooting protection module. The power output stage is used for generating an output signal to drive a load device. The PWM signal generator generates a pulse width modulation (PWM) signal which is used for controlling the power output stage. The compensation module is used for generating a compensation signal to the PWM signal generator according to the output signal. The overshooting protection module receives the output signal to enable or disable the PWM signal generator.