A composite magnetic component is provided. The composite magnetic component includes a magnetic flux-guiding unit, a first coil structure and a second coil structure. The first coil structure and the second coil structure are wound around a first winding portion and a second winding portion of the magnetic flux-guiding unit, respectively. A first magnetic flux results from the first coil structure and the magnetic flux-guiding unit. A second magnetic flux results from the second coil structure and the magnetic flux-guiding unit. The first magnetic flux is orthogonal to the second magnetic flux within the magnetic flux-guiding unit.