The utility model discloses a take coupling inductance's high -power two -way DCDC converter of buck -Boost type, its characterized in that constitutes by the two -way buck -Boost circuit in N way is parallelly connected, N >= 2, and N is natural number, respectively the inductance adoption magnetism coupling inductance of two -way buck -Boost circuit. The utility model discloses a coupling inductance, this inductance under the same parallelly connected common mode inductance's condition, have the differential mode flow equalize the inductance big, flow equalize effectually, install small, small in noise and a great deal of advantage such as efficient, can improve equivalent switching frequency, high conversion efficiency is carried to reduction work noise and inductance volume. The utility model discloses the DCDC converter can step up on single direction and also can step down, so the range of application is very extensive.