Isolation transformer, common mode inductor, electronic component and preparation method thereof

The invention discloses an isolation transformer, a common mode inductor, an electronic component and a preparation method thereof. The isolation transformer comprises a substrate, a substrate, a first coil, a second coil, a magnetic core and a packaging layer, the substrate is located on the base plate; the first coil, the second coil and the magnetic core are all located in the substrate, and the first coil and the second coil both penetrate through a middle through hole of the magnetic core and radially wind the magnetic core; the two ends of the first coil are connected with the substrate through first connecting lines respectively. The packaging layer is formed on the substrate, and the substrate, the first coil, the second coil and the magnetic core are all located in the packaging layer; a portion of the encapsulation layer is located between the first coil and the second coil and can separate the first coil from the second coil. The first coil and the second coil do not need to be intertwined by ename