Aiming at the problems of high input harmonics in SWISS rectifiers under traditional control strategies, as well as noise amplification caused by differential calculation and poor dynamic performance during sudden load changes, this paper proposes a dual - loop control strategy for SWISS rectifiers combining error - based active disturbance rejection control (EADRC) and PI control. First, the output error is calculated, and the unknown dynamic disturbances of the output error are unified with other disturbances. Subsequently, a Luenberger observer is employed to obtain the estimated values of the output error states and total disturbances. Finally, an approximation function is designed to approximate the dynamic characteristics of the controlled object, thereby enhancing the dynamic tracking performance and robustness of the system. Simulation results show that the proposed strategy improves both the system response speed and anti-interference performance, enabling the SWISS rectifier to exhibit excellent dynamic and static performance under operating conditions such as sudden load changes and sudden output voltage changes.