In order to solve the problems of insecure sealing and package burning through in the sealing device of betel nut automatic packaging machine, a control system of sealing device of betel nut automatic packaging machine based on PLC (programmable logic controller) technology was designed to achieve the stability of betel nut packaging. Introduction of sealing device process and control system structure, including PLC, temperature sensor, position sensor, temperature control module, servo motor, etc. The temperature in the sealing device is the main object of study, and in order to make up for the shortcomings of traditional PID (proportional-integral-differential) control and improve the traditional LADRC (linear active disturbance rejection control) control parameters adjustment difficulties and other problems, a particle swarm optimization improved linear self-anti-disturbance temperature controller was proposed to improve the robustness and anti-disturbance of the sealing device temperature control. Finally, simulation and experimental studies were performed. The results show that compared with the traditional PID as well as the ADRC (active disturbance rejection control) controller, the improved LADRC method optimized by adding the PSO (Particle Swarm Optimization) algorithm can make the system output response, rapidity enhancement, shorter regulation time, and the actual packing temperature error of the sealing device < 0.4 ℃. It can be seen that the mentioned sealing device system effectively improves the temperature control accuracy and enhances the productivity of betel nut automatic packaging machine to a certain extent.