In order to solve the problem of poor anti-interference ability of the permanent magnet synchronization motor in the direct torque control system, the speed loop adopts the active disturbance rejection controller (ADRC) to replace the traditional PI controller, removes the tracking differentiator in the ADRC to improve the system signal tracking rate, and reduces the burden of the ADRC through introducing the load observation to feed-forward compensation on the speed loop. Meanwhile, considering the interference caused by DC offset in current sampling, the traditional voltage model is filtered by a second-order high-pass filter and the second-order high-pass filter is discretely processed by the trapezoidal discretization method, which improves the observation accuracy of the observer. The filter cutoff frequency is set to follow the change of the electrical angular velocity so that the dynamic performance of the system is improved. Finally, simulation results suggest that the system output speed is super-adjustment, the output magnetic chain, high torque accuracy, and good anti-interference ability.