A control method for bidirectional DC-DC converter includes: operating a bidirectional DC-DC converter having a low voltage side including a plurality of low-voltage-side switches, a voltage clamping switch and a voltage clamping capacitor, and a high voltage side including a plurality of high-voltage-side switches in a boost mode; switching the voltage clamping switch with a predetermined duty cycle prior to switching on all of the low-voltage-side switches; adjusting the predetermined duty cycle of the voltage clamping switch to be smaller than a turn-off interval of the low-voltage-side switches to reduce the conduction loss of the low-voltage-side switches and the voltage clamping switch; alternatively, operating the DC-DC converter in a buck mode; and adjusting and extending the duty cycle of the low-voltage-side switches to overlap a turn-off time of the high-voltage-side switches to reduce the conduction loss of the low-voltage-side switches.