A soft-switching auxiliary circuit is provided, which may be applicable to a converter including a first main switch and a second main switch. The soft-switching auxiliary circuit may include a first auxiliary switch, a second auxiliary switch, a first energy adjustment module and a second energy adjustment module. By means of the first auxiliary switch and a second auxiliary switch, the first energy adjustment module and the second energy adjustment may properly store and adjust the energy of the converter; therefore, both the first main switch and the second main switch of the converter can achieve soft-switching.