The work aims to improve the working accuracy of automation equipment in the packaging industry, optimize the stability of the sensorless control system of the traditional permanent magnet synchronous motor, and improve the system robustness and anti-disturbance performance when the motor encounters internal and external disturbances. A super-twisting sliding mode was introduced to design a super-twisting sliding mode MRAS observer to improve the stability of the system. Simultaneously, according to the good dynamic tracking performance of the sliding mode disturbance observer for the motor, the super-twisting sliding mode algorithm was used to optimize its performance. Besides, a combined control strategy of a super-twisting sliding mode MRAS observer and a super-twisting sliding mode disturbance observer for permanent magnet synchronous motors was proposed. This scheme effectively reduced the speed estimation error when the motor encountered disturbances, and the error fluctuated around 0.8 r/min, which significantly improved the response speed of the motor control system after encountering disturbances. The experimental simulation is carried out in MATLAB/SIMULINK, and the results verify that the control strategy proposed not only improves the robustness and tracking accuracy of the system, but also strengthens the anti-interference ability of the system.