Under the condition of asymmetric fault, there is a large difference between the electromechanical transient simulation results of the wind power system and the electromagnetic transient simulation results, which seriously affects the accuracy of the stability evaluation of the simulation system. In order to reduce the error between wind power system electromechanical transient simulation and electromagnetic transient simulation under the condition of system asymmetry, this paper presents a method to modify the characteristic curve of electromechanical transient simulation of wind power system based on data mining. And the main error evaluation indexes of electromechanical simulation are given. Finally, this paper takes the electromagnetic transient simulation curve of PSCAD/EMTDC as the standard response curve, and takes the PSASP wind power system electromechanical transient simulation curve as the goal, to verify through the construction of the corresponding sample library and correction examples. The simulation results show the validity of the proposed method and the rationality of the evaluation index.