The present invention provides a power supply circuit and a power supply method. The power supply circuit comprises: a charge control unit, a battery and battery protection unit, a voltage stabilizing unit and a voltage boosting unit; the voltage boosting unit comprises: a consumption reducing module for, at the moment of turning on or turning off a power device in the voltage boosting unit, enabling an electric current flowing through the power device to be zero. The present invention, by arranging the consumption reducing module, enables an electric current flowing through the power device to be zero at the moment of turning on or turning off the power device in the voltage boosting unit, which realizes zero current turn-on or turn-off of the power device, and reduces consumption of the electric energy.