The invention discloses a bidirectional DC/DC converter. According to the bidirectional DC/DC converter, capacitance values of a first capacitor at a first side and a second capacitor at a second side is a filtering capacitor value required by a low voltage side of the bidirectional DC/DC converter, the bidirectional DC/DC converter is provided with a switching assembly and a capacitor tank, the capacitor tank can be connected in parallel with the first capacitor or the second capacitor through the switching assembly. In an operation process of the bidirectional DC/DC converter, a filtering capacitor at the low voltage side does not generate an over-design problem, through connecting a capacitor at the high voltage side in parallel with the capacitor tank, the capacitance value of the filtering capacitor at the high voltage side can be improved, so demands of the filtering capacitor of the high voltage side are satisfied, and thereby demands of the filtering capacitors of the high voltage side and the low voltage side of the bidirectional DC/DC converter can be all satisfied. The invention further discloses a control method for the bidirectional DC/DC converter.