Aiming at the problems of voltage overshoot and current surge caused by parallel active power filter ( SAPF) grid connection under traditional control mode. Based on the protection of switching devices and line overcurrent protection from excessive current, the article analyzes the causes of voltage overshoot and current impact by establishing a mathematical model of SAPF DC side. After the above work, the transition process and first-order auto disturbance rejection control are introduced on the basis of the traditional series current limiting resistor start strategy, and a first-order auto disturbance rejection SAPF grid-connected start strategy with transition process is designed, which verifies the stability of the first-order active disturbance rejection control. The proposed startup strategy was verified in the simulation software, and compared with the traditional proportional integral (PI) control method in the simulation, the validity and feasibility of the proposed startup strategy were verified. Finally, through the simulation analysis, this startup strategy can suppress the inrush current generated during the grid-connected startup process of the system within 100 A. Compared with the traditional control strategy of 500 A, the inrush current greatly suppresses the damage to the grid; The voltage overshoot during grid connected startup is 0, and the SAPF has no impact start.