A power conversion circuit includes an input positive terminal, an input negative terminal, an output positive terminal, an output negative terminal, a first bridge arm, a second bridge arm, a transformer, a first resonant capacitor, a second resonant capacitor, a third resonant capacitor and a third resonant capacitor. The transformer includes a first winding, a second winding and a third winding. The plurality of switches in the first bridge arm and the plurality of switches in the second bridge arm are selectively turned on or turned off. The ratio of the input voltage to the output voltage can be adjustable by changing the turn numbers of the first winding, the second winding and the third winding.