A power converter and a power converting method are provided. The power converter for converting an ac input voltage at an input terminal thereof into an ac output voltage at an output terminal thereof includes an energy-storing inductor, a first switching circuit coupled to the energy-storing inductor to selectively switch so that the input terminal of the power converter is coupled to the energy-storing inductor, a second switching circuit coupled to the energy-storing inductor and the first switching circuit to selectively switch so that a common terminal of the power converter is coupled to the energy-storing inductor; and a third switching circuit coupled to the energy-storing inductor, the first switching circuit and the second switching circuit to selectively switch so that the output terminal of the power converter is coupled to the energy-storing inductor.