A DC-DC converter includes a power conversion circuit for converting a DC input voltage to a DC output voltage; and an active clamp circuit for soft switching a first active switching element of the power conversion circuit and recovering leakage inductance energy of a main transformer of the power conversion circuit. As such, the present disclosure provides a DC-DC converter that reduces the switching loss of the switching elements and effectively recovers the leakage inductance energy, thus increasing the conversion efficiency of the converter.