Abstract: With the scale networking of wind power generation,voltage issues in the power system have become increasingly prominent.To improve the transient response characteristics of doubly-fed induction generator wind farm during grid faults,a hierarchical reactive power support strategy based on active disturbance rejection control（ADRC）is proposed. Firstly,the reactive power boundaries of doubly-fed induction generator（DFIG）is described. Secondly,a layered reactive power support strategy for doubly fed wind farms is designed,ADRC is utilized in the station controller to generate voltage control signals and employ variable gain coefficient assistance in unit controller to adjust the voltage. Finally,Washout filters are used to suppress transient overvoltage. A simulation model of doubly fed wind farm based on EMTP-RV is constructed. The simulation analysis shows that the proposed control strategy has good support effect when the grid voltage drops.