A transformer module, comprising: a magnetic core, comprising at least one magnetic column being at least partially covered by a multi-layer carrier, wherein the multi-layer carrier comprises a plurality of horizontal wiring layers, at least one insulating layer, a plurality of horizontal copper foils and a plurality of connecting copper foils, each of the insulating layers is located between adjacent horizontal wiring layers, each of the horizontal copper foils is located on a horizontal wiring layer, and the connecting copper foil is disposed to connect the horizontal copper foils located on different horizontal wiring layers; and a first winding and a second winding surrounding the magnetic column, and the second winding being located outside the first winding; wherein the first winding comprises at least two horizontal copper foils of the plurality of the horizontal copper foils and at least two connecting copper foils of the plurality of the connecting copper foils; the second winding comprises at least two horizontal copper foils of the plurality of the horizontal copper foils and at least two connecting copper foils of the plurality of the connecting copper foils; a first end of the first winding is electrically connected to a first surface-mounted pin through a first via; a second end of the first winding is electrically connected to a second surface-mounted pin through a second via; and the first via and the second via pass through at least one insulating layer; a first end of the second winding is electrically connected to a third surface-mounted pin; a second end of the second winding is electrically connected to a fourth surface-mounted pin; the first surface-mounted pin, the second surface-mounted pin, the third surface-mounted pin and the fourth surface-mounted pin are disposed on at least one surface of the transformer module. a magnetic core, comprising at least one magnetic column being at least partially covered by a multi-layer carrier, wherein the multi-layer carrier comprises a plurality of horizontal wiring layers, at least one insulating layer, a plurality of horizontal copper foils and a plurality of connecting copper foils, each of the insulating layers is located between adjacent horizontal wiring layers, each of the horizontal copper foils is located on a horizontal wiring layer, and the connecting copper foil is disposed to connect the horizontal copper foils located on different horizontal wiring layers; and a first winding and a second winding surrounding the magnetic column, and the second winding being located outside the first winding; wherein the first winding comprises at least two horizontal copper foils of the plurality of the horizontal copper foils and at least two connecting copper foils of the plurality of the connecting copper foils; the second winding comprises at least two horizontal copper foils of the plurality of the horizontal copper foils and at least two connecting copper foils of the plurality of the connecting copper foils; a first end of the first winding is electrically connected to a first surface-mounted pin through a first via; a second end of the first winding is electrically connected to a second surface-mounted pin through a second via; and the first via and the second via pass through at least one insulating layer; a first end of the second winding is electrically connected to a third surface-mounted pin; a second end of the second winding is electrically connected to a fourth surface-mounted pin; the first surface-mounted pin, the second surface-mounted pin, the third surface-mounted pin and the fourth surface-mounted pin are disposed on at least one surface of the transformer module.