A power detector includes a detection circuit and a bias circuit. The detection circuit is used to receive an input signal and output a power indication signal. The bias circuit includes a first impedance unit, a second impedance unit and a transistor. The transistor includes a first terminal and a control terminal coupled to the first impedance unit, and a second terminal. The second impedance unit is coupled between the first terminal of the transistor and an output terminal of the bias circuit, or between the second terminal of the transistor and a second terminal of the bias circuit. The output terminal of the bias circuit is coupled to an input terminal of the detection circuit, and is used to output a bias signal.