The threephase hybrid stepping motor (THBSM) is equivalent to the permanent magnet synchronous motor(PMSM) running at low speed, which can be controlled by the advanced control method of synchronous motor. Based on the theory of auto disturbance rejection controller (ADRC), a novel method of sensorless vector control for THBSM is proposed, which transforms THBSM under the threephase static coordinate system to the twophase rotating coordinate system. The action of the speed and the d axis current on the q axis current is considered as the disturbance of the torque current loop. Using MATLAB/Simulink to build the simulation model, the simulation results demonstrate the effectiveness of the proposed method.