A method and device for detecting inductor current of a PFC circuit are disclosed, which relates to the field of power supply technology. The method includes: detecting a voltage on a boost inductor of a critical-conduction mode PFC circuit, and obtaining an inductor voltage detection signal (S1); converting the inductor voltage detection signal into a voltage signal whose waveform is consistent with a current waveform of the inductor to serve as an inductor current detection signal, to perform loop protection on the PFC circuit or perform over-current protection on the PFC circuit by using the inductor current detection signal (S2).