A method for controlling a supply voltage of a power amplifier, and an electronic device are provided. The method includes acquiring a state of an envelope of a to-be-amplified signal, where the state of the envelope includes a rising edge and a falling edge; acquiring a first voltage corresponding to the envelope when the state of the envelope is the falling edge, and controlling the supply voltage of the power amplifier according to the first voltage. The method also includes acquiring a second voltage corresponding to a maximum peak value of the to-be-amplified signal in a first preset time when the state of the envelope is the rising edge, and controlling, according to the second voltage, the supply voltage of the power amplifier in the first preset time.