Abstract: In the context of a high proportion of power electronic equipment being integrated into the power system, the transient synchronization stability problem of grid connected renewable energy system is becoming increasingly prominent. However, there is little research on the impact of active power restored rate in the post-fault stage on the transient synchronization stability of grid-connected renewable energy system. This paper defines the equivalent power angle and derives the equivalent rotor swing equation in this stage; Based on the equivalent equal area criterion, analyze the transient synchronous stability characteristics of the system under different power restored rates. Theoretical analysis shows that reducing the active power restored rate can avoid power imbalance, reduce acceleration area, and significantly improve the transient synchronization stability of renewable energy system during the post-fault stage. Simulation results verified the validity of the analysis.