In this paper, an equivalent model is established for the analysis object of the doubly-fed wind power centralized connection receiving-end large system, and the analysis is carried out based on the power angle characteristics and transient characteristics of the doubly-fed wind turbine. First of all, the electromagnetic power analysis expression of the synchronous machine of the single-ended power transmission system is adopted to analyze the influence of the equivalent output of wind power to replace the thermal power output and connect to the system on the initial power angle of the synchronous machine. Secondly, by studying the characteristics of the active power of the doubly-fed fan after a fault occurs, and analyzing the influence on the system's transient power angle stability based on the Equal Area Rule. The research results show that when the wind power is connected to the system, the initial power angle of the synchronous machine decreases and the transient stability increases; the active power characteristics of the doubly-fed wind turbine have a positive effect on the transient power angle stability of the system.