A sensorless switch magnetic resistance motor-driven system belongs to the motor control field, and comprises a switch magnetic resistance motor, an asymmetric converter, a bus capacitor, a DC power supply, a driving circuit, a current regulator, a backstepping controller, a non-linear state observer, a current hall sensor, a current signal conditioning circuit, a voltage hall sensor, and a voltage signal conditioning circuit; the sensorless structure can increase the system stability; the non-linear state observer can monitor the stator-phase voltage and phase current so as to calculate therotor position, thus accurately determining the rotor position even the motor is under a high speed rotating state, reducing the system cost, and improving the driving precision.