A power module, comprising: a transformer, comprising: a magnetic core (31, 191) comprising at least one magnetic column, a first wiring layer, a first insulating layer and a second wiring layer, the first wiring layer, the first insulating layer and the second wiring layer being sequentially disposed on the magnetic core (31, 191) from inside to outside; a first metal winding, wound around the magnetic core (31, 191) in a foil structure, comprising a first winding segment formed in the first wiring layer and a second winding segment formed in the second wiring layer, wherein a first end of the first winding segment is electrically connected to a first end of the second winding segment through a first connector, a second end of the first winding segment is electrically connected to a first pin through a second connector, and a second end of the second winding segment electrically connects to a second pin; a second metal winding, wound around the magnetic core (31, 191) in the foil structure, comprising a third winding segment formed in the first wiring layer and a fourth winding segment formed in the second wiring layer, a first end of the third winding segment is electrically connected to a first end of the fourth winding segment through a third connector, a second end of the third winding segment is electrically connected to the first pin through a fourth connector and a second end of the fourth winding segment electrically connects to a third pin; wherein the first connector, the second connector, the third connector and the fourth connector each pass through the first insulating layer; wherein with the foil structure, a dimension of a winding parallel to a longitudinal direction of the magnetic column is W, a thickness of the winding which is a dimension of the winding vertical to the magnetic column is H, and H and W satisfy a relationship: W>10H. a magnetic core (31, 191) comprising at least one magnetic column, a first wiring layer, a first insulating layer and a second wiring layer, the first wiring layer, the first insulating layer and the second wiring layer being sequentially disposed on the magnetic core (31, 191) from inside to outside; a first metal winding, wound around the magnetic core (31, 191) in a foil structure, comprising a first winding segment formed in the first wiring layer and a second winding segment formed in the second wiring layer, wherein a first end of the first winding segment is electrically connected to a first end of the second winding segment through a first connector, a second end of the first winding segment is electrically connected to a first pin through a second connector, and a second end of the second winding segment electrically connects to a second pin; a second metal winding, wound around the magnetic core (31, 191) in the foil structure, comprising a third winding segment formed in the first wiring layer and a fourth winding segment formed in the second wiring layer, a first end of the third winding segment is electrically connected to a first end of the fourth winding segment through a third connector, a second end of the third winding segment is electrically connected to the first pin through a fourth connector and a second end of the fourth winding segment electrically connects to a third pin; wherein the first connector, the second connector, the third connector and the fourth connector each pass through the first insulating layer; wherein with the foil structure, a dimension of a winding parallel to a longitudinal direction of the magnetic column is W, a thickness of the winding which is a dimension of the winding vertical to the magnetic column is H, and H and W satisfy a relationship: W>10H.