The invention provides a magnetically controlled reactor and a method thereof. The magnetically controlled reactor comprises a closed-loop iron core. The closed-loop iron core is provided with two iron core columns, a first iron core column is provided with a first coil and a third coil, a second iron core column is provided with a second coil and a fourth coil, the dotted terminals of the first coil and the second coil are connected with a first terminal, the terminal of different magnetic polarity of the first coil is connected with the dotted terminal of the fourth coil, the terminal of thedifferent magnetic polarity of the second coil is connected to the dotted terminal of the third coil, the terminals of different magnetic polarity of the third coil and the fourth coil are connectedwith a second terminal, and the terminals of different magnetic polarity of the first coil and the second coil are connected to an IGBT module and a two-electrode tube in a parallel mode, and the IGBTmodule and the two-electrode tube are connected in series; the controlling terminal of the IGBT module is connected with a controlling circuit; according to the magnetically controlled reactor and the method thereof, resistance adding is unnecessary, and the structure is simple.