Abstract: When the wind farm is connected to the power grid,the traditional directional element is susceptible to the interference of the dynamic characteristics of the power electronic devices inside the wind farm when the short-circuit fault occurs,which leads to the frequency characteristic deviation,system parameter instability and weak feedability,so that the relay protection device cannot judge the fault area timely or correctly. In order to solve the above problems,the fault additional network containing wind farms is analyzed first,and the correlation between the electrical quantities of each measurement point at the pilot protection installation after the fault occurs is found,and the fault logic relationship is determined. Then,through the analysis of the common decoupling mode of phasemode transformation,a reasonable method is selected to replace the correlation expression,and the fault region is determined according to the correlation coefficient value. Finally,PSCAD/EMTDC is used to build the doubly-fed wind farm grid-connected model and various fault types and scenarios are set. Matlab is used to verify to test the judgment results of the fault area to determine the correctness and rationality of the proposed method. Simulation results show that this method has high reliability.