Abstract: Disclosed is a magnetic integrated device including a first magnetic core plate and N magnetic elements, one of which is connected to the first magnetic core plate. Excitation currents of the N magnetic elements have phases different from each other by 360/N degrees, and excitation directions of adjacent magnetic elements are opposite, wherein N is an integer greater than or equal to 2. Each magnetic element includes a first magnetic core including a first magnetic core body, a first magnetic column and two first side columns fixed on the same side of the first magnetic core body, and a combined winding including a secondary winding and a primary winding which are wound around the first magnetic column, wherein a extension direction of the first magnetic column is towards the first magnetic core plate. Therefore, the cost, power consumption and space volume are reduced, and the power density is improved.