The invention discloses a Doherty power amplifier and an implementation method thereof. A peak amplifying circuit of the Doherty power amplifier consists of a radiofrequency switch circuit used for controlling turn-on of the peak amplifying circuit, a final-stage carrier amplifier of a carrier amplifying circuit of the power amplifier is a HVHBT (high-voltage heterojunction bipolar transistor) device, and a final-stage peak amplifier of the peak amplifying circuit of the power amplifier is a GaN device. By the aid of the Doherty power amplifier and the implementation method thereof, the shortcoming that a peak branch of an existing Doherty power amplifier is turned on in advance is overcome, power consumption of the peak amplifier is reduced, and batch efficiency of the integral Doherty power amplifier is improved.