The invention discloses a digital monocyclic control method of a PFC converter. The method comprises the following steps: firstly, sampling an output voltage and an inductor current, adopting a digital signal processor so that an output voltage sampling value passes by a voltage PI adjusting ring while utilizing the synchronous sampling function of the digital signal processor to finish the peak value sampling of the inductor current so as to ensure the monocyclic control requirements; and then obtaining a PWM control signal of a power device by a digital monocyclic core control algorithm. The digital monocyclic control method can be adopted to effectively simplify the digital control structure of PFC, improves the real-time computational capability and the control effect of a system and overcomes the adverse influence of discrete parameters of devices, such as operational amplifiers, capacitors, and the like in a traditional monocyclic control resettable integrator. In addition, the system fully keeps the accordance between a sampling interface and traditional PFC while fully keeping the advantages such as precisely controlled precision, perfect communication capability, and the like of traditional digital control.