The present disclosure provides an on-board charger including a power supply terminal, a switching circuit, a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first bus capacitor, a second bus capacitor, a first switch and a control circuit. The present disclosure can realize a compatibility of a single-phase power supply input or a three-phase power supply input through the cooperation of the switching circuit with the control circuit. Meanwhile, the number of bus capacitors is reduced in the operating state of the single-phase power supply input, accordingly not only the volume and cost of the on-board charger can be reduced, but also the charging power of the on-board charger can be increased, which has an advantage of strong applicability.