The present invention discloses a multi-phase switch-mode power supply (SMPS). The multi-phase SMPS may comprise a plurality of comparing circuits and a controller. Wherein each comparing circuit comprises a first input coupled to a threshold voltage, a second input coupled to a feedback signal of the output voltage, and an output configured to provide a load indication signal. The controller may have a plurality of inputs coupled to the outputs of the comparing circuit, and a plurality of outputs configured to provide control signals for driving a plurality of switches of the multi-phase SMPS. And the controller is configured to selectively turn on a plurality of the switches according to the load indication signals.