The present disclosure provides a power conversion circuit including positive and negative input terminals, a clamping branch circuit, a first primary switch, a transformer, a rectifier circuit, a resonant inductor, a resonant capacitor, and positive and negative output terminals. The clamping branch circuit includes a clamping capacitor and a second primary switch serially connected between the first and second terminals thereof. The first terminal is coupled to the positive input terminal. The first primary switch is connected between the second terminal and the negative input terminal. The primary winding of the transformer is connected to the clamping branch circuit in parallel. The rectifier circuit includes first and second bridge arms connected in parallel. Connection terminals in the first and second bridge arms are coupled to two terminals of the secondary winding of the transformer correspondingly. The first and second bridge arms are coupled between the positive and negative output terminals.