Abstract: The Phase Ⅵ wind turbine blade was taken as the research object,and the blade element at r/R=30%,63% and 95% were used as reference to establish the blade model with the same spanwise distribution of the attached vortex circulation of the wind turbine blade at the test wind speed of 7,9 and 15 m/s to analyze the influence mechanism of the trailing vortex on the aerodynamic performance of the local airfoil of the wind turbine. SST k-ω turbulence model with transition effect was adopted to analyze and compare the aerodynamic characteristics of the established blade model and the two-dimensional S809 airfoil. The results show that the trailing vortex of the rotating blade has a restraining effect on the separation phenomenon,which weakens with the increase of angle of attack;The influence of trailing vortex shows multiple effects. Besides decreasing angle of attack of the local airfoil,the negative pressure coefficient of the suction surface and the positive pressure coefficient of the pressure surface are also reduced.