Abstract: Due to the problem of participation of multi-control link and difficulty in analyzing the multi-parameter coupling in the subsynchronous oscillation of doubly fed induction generator (DFIG) system connected to power grid via series compensation, the impedance sensitivity analysis of DFIG based on Sobol method and the parameter coordination optimization method are proposed. Firstly, according to the impedance method based on space vector, the mathematical model of DFIG and rotor side converter (RSC) is established, and the analytical expression of equivalent impedance of DFIG system including rotor side control link is deduced. Secondly, the Sobol method is used to analyze the impedance sensitivity, quantify the influence of each parameter, and calculate the quantitative index to evaluate the coupling relationship between parameters. Then, the parameter-joint-adjustment stability region considering multiple influencing factors is obtained, and a multi-parameter coordinated optimization strategy is proposed. Finally, the time-domain simulation model of doubly fed fan connected to the grid through series compensation is built in MATLAB/Simulink to verify the correctness of parameter influence analysis and parameter-joint-adjustment stability region.