This paper mainly describes the operating principles and parameter analysis of the reluctance brushless d c motor. The magnetic suspension technique is used to support the rotor shaft in order to increase the lifetime of the brushless d c motor. The rotor of our magnetic suspension momentum wheel is made of silicon steel pieces，so that the brushless d c motor chooses the reluctance-motor form. As the logistic circuit and the driving one are successfully developed by us，the motor of the magnetic suspension momentum wheel selects the three-phase stator of two pairs pole and the step spinning magnetic field at an electric angle of 60 degrees.