A PFC converter and a control method thereof are provided. The PFC converter includes a first bridge, an inductor, a second bridge and a control unit. The first bridge includes a first switch and a second switch connected in series. There is a first node between the first and second switches. Two terminals of the inductor are coupled to the first node and a first terminal of an AC power source respectively. The second bridge includes a third switch and a fourth switch connected in series. There is a second node between the third and fourth switches, and the second node is coupled to a second terminal of the AC power source. The control unit controls a ratio of a high level duration on the second node in every line frequency cycle to be smaller than (250/Vbus)2, where Vbus is an output voltage of the PFC converter.