This application discloses a voltage scaling method and an electronic device. The method is applied to an electronic device having a processor and a power supply that supplies power to the processor. The method includes the processor sending power supply scaling information to the power supply based on an operating frequency in a next time period. The method further includes the power supply determining, based on the power supply scaling information, a supply voltage Vout used to supply power to the processor. The supply voltage Vout decreases as a load current of the power supply increases. Vmin≤Vout≤V, where Vmin is a lowest supply voltage of the processor at the operating frequency in the next time period, and V is a specified supply voltage of the processor at the operating frequency in the next time period.