The invention discloses a device for bypassing ripple of inductive current in area of switch power supply. The device includes energy storgae inductance L, topological circuit of direct to direct power inversion and a group of coils Np. Said coil Np is coupled with inductance coil Ns on magnetic core of the energy storage inductance L, and their like ends are connected. Said connected point is connected to the topological circuit. Unlike end of coil Np is connected to inductance Lext. The other end of the inductance Lext is connected to capacitor C, and the other end of capacitor C is connected to internal reference ground of the switch power supply. The device has advantages of small quantity of inductance and capacity, small volume, lightweight, low cost and good performance of closed loop control.