The work aims to solve the problems of slow packaging speed and worrying packaging quality of traditional packaging machinery, so as to meet the requirements of high efficiency and high precision of packaging machinery, and improve the automation level of food packaging and the economic benefits of packaging enterprises.For the permanent magnet synchronous motor with great potential, the controller and control method were studied and improved, and finally the active disturbance rejection controller was selected. The non-smooth function fal in the active disturbance rejection controller was improved to obtain a continuous and smooth tal function to reduce the flutter around the origin, and the nonlinear state error feedback rate and extended state observer were redesigned based on the tal function to achieve better control effect of permanent magnet synchronous motor. From the simulation results, tal function had better smoothness and continuity than fal function. The permanent magnet synchronous motor based on improved ADRC had better dynamic performance, steady-state accuracy, anti-interference ability and tracking ability. The optimized permanent magnet synchronous motor servo control system is suitable for occasions with high precision and frequent load changes and can effectively improve the level of packaging automation and meet the requirements of packaging industry such as high efficiency and high precision.