The work aims to solve the problem of low precision in packaging machines in work due to the slow dynamic response and weak disturbance rejection ability of permanent magnet synchronous motors. A dual-mode finite time sliding mode controller was designed to realize finite time convergence of the system. By adding a dual-mode function to the reaching law, it could make the sliding mode gain achieve large error and large gain, small error and small gain , and the time of the sliding mode gain switched to small gain was adjustable, so that the motor could achieve faster response speed and less chattering. At the same time, a finite time disturbance observer was designed to observe the disturbance, and feed-forward compensation was performed to improve the disturbances rejection performance of the motor. The experimental results showed that if the method proposed was used to control the motor, compared with the control groups, the dynamic response was improved by 27% and 37% and the control performance was improved by 40% and 70%. Compared with the super-spiral disturbance observer, the disturbance rejection performance of the motor was improved by 58%. Therefore, the control strategy proposed can significantly improve the dynamic response, control performance, and disturbance rejection ability of the system, which will let permanent magnet synchronous motor more suitable for the needs of packaging machines.