Current doubler rectifier is widely used as a low voltage and high current topology. In power modules, due to the large size of the magnetic parts of the transformer and inductor, in order to improve the power density, the inductor and transformer are usually integrated into a magnetic core by magnetic integration technology, thereby reducing the overall volume. However, in order to further reduce the core size, it is often necessary to increase the air gap of the core to prevent core saturation, but the change of air gap makes the equivalent steady-state inductance at the output smaller, worsening the output current ripple. In this paper, the magnetic flux density in the core is reduced by adding additional winding while keeping the output current ripple size constant, thereby reducing the core volume and increasing the power density. In addition, the influence of the air gap position in the core on the topology was studied.