Variable-modal bridgeless PFC circuit

The invention discloses a variable-modal bridgeless PFC circuit. The circuit comprises an inductor, a first bidirectional switch, a second bidirectional switch, a first half-bridge structure, a second half-bridge structure and a third half-bridge structure. The three half-bridge structures are connected in parallel to serve as an output end. The first bidirectional switch is connected between the first and second half-bridge structures, and the second bidirectional switch is connected between the second and third half-bridge structures. Two ends of the first bidirectional switch are in series connection with the inductor to serve as the input end. The working mode can be flexibly adjusted according to the size of an inputted voltage, and the switching frequency is reduced in a three-level mode, so as to reduce the switching loss, and improve the circuit efficiency. The circuit solves a problem that the circuit efficiency is low in the prior art when an inputted voltage is low, achieves high efficiency and low common-mode noise in the whole range, and improves the overall performance.