The present invention relates to a reluctance motor and its excitation method has an electrical excitation permanent magnetic switch and the electrical excitation permanent magnetic switch. Led by the permanent magnetic body of permanent-magnetic switch (12) two magnetic poles and field coil (11) both ends of the iron core that is wound of the each of the two soft magnetic material (12), poles on the soft magnetic material ( 14, 15) is installed. motor is a permanent magnetic switching the basic module of the stator and rotor. And two magnetic poles of each module is disposed in the axial direction, between the salient poles of the stator of the module and the rotor modules are relatively disposed and leaving an air gap, on positions symmetrical axis fixed field coil of a child of the module and the rotor of the module leads entered the excitation control power as each one phase line after the series connection or parallel connection. And a joint for between the motor itself, provide electrical excitation simultaneously to two phase modules of the rotational position deviation configured prefabricated motor and the stator. In this electrical excitation permanent magnetic switch and the electrical excitation permanent magnetic switch reluctance motor is energy saving, the magnetic loss is small, there is a high magnetic efficiency; it is using the prefabricated motor, electrically excited by a bi-phase, a step angle subdivision realized, working is a smooth, increase the output efficiency and control accuracy.