A converter circuit includes a capacitor module and a balance module. The capacitor module includes at least a first capacitor and a second capacitor. The balance module includes at least a first resonant circuit. The first resonant circuit includes at least two switch groups connected in parallel and a first resonant cavity bridged between the two switch groups. The first capacitor and the second capacitor are connected in series. The first resonant circuit is separately bridged between two ends of the first capacitor and between two ends of the second capacitor. The balance module controls each switch in the first resonant circuit, so that each switch works with the first resonant cavity to affect a current, to balance a voltage between the two ends of the first capacitor and a voltage between the two ends of the second capacitor.