The invention discloses an asynchronous motor vector controlling magnetic field orientation correcting method based on torque observation and belongs to the field of asynchronous motor speed regulation. The method relates to a field current loop, a torque current loop, rotor field orientation, stator flux linkage identification, torque observation, space vector modulation, a three-phase full-bridge inverter and an asynchronous motor. Magnetic field orientation correction is achieved by means of the torque observation difference under the dq and alpha beta coordinate systems. Due to the fact that a stator flux linkage is observed directly and observation of a rotor flux linkage is not needed, parameter change on the rotor side does not influence a magnetic field orientation correction system, and parameter robustness is high. An orientation correction model is clear in theory and simple in structure. The method has broad application prospects in asynchronous motor vector control type speed regulation.