The work aims to enhance the rapid response, and anti-interference capabilities of permanent magnet synchronous motors (PMSM) during filling, sealing, and other packaging operations, while reducing the vibration of the control system. A composite sliding mode control strategy was proposed and a segmented rate reaching law adaptable to the sliding surface and system state variations was designed. Then, it was combined with a novel integral sliding mode surface to design a speed loop sliding mode controller. Furthermore, a disturbance observer was designed to estimate the disturbance in the closed-loop system, and the estimated value was compensated to the output current of the controller in real time to construct a composite controller. Simulation results demonstrated that the designed controller significantly improved the convergence rate and effectively reduced the vibration of the control system, thereby enhancing the dynamic quality. In addition, the disturbance estimated by the disturbance observer improved the anti-interference capability of the system, further enhancing the control performance. The control strategy of the proposed composite sliding mode controller effectively improves the dynamic performance and anti-interference capability of the PMSM speed control system, reduces the vibration of the control system, and provides an effective solution for achieving efficient and stable control.