The invention discloses a differential converter based on a Boost circuit and a Buck-Boost circuit and an application thereof. The differential converter includes the Boost circuit and the Buck-Boostcircuit. A first bridge arm is connected to a second bridge arm in series, and the other end of the second bridge arm is connected to an AC side through an LC filter. A first inductor and a second inductor are connected to one end of a DC side in series, and the other end of the DC side is connected to a connection point between an inductor element and a capacitor element in the LC filter. The secondary ripple power is stored by the Boost circuit, and therefore, the secondary ripple of the DC side is reduced.