Abstract: Through applying jet technology to the trailing edge of the airfoil,the aerodynamic performance of the wind turbine can be effectively improved,obtaining the similar effect with the Gurney flap in lift improvement. In this paper,based on the trailing edge jet of the NACA0018 airfoil. The comparison and the analysis on the aerodynamic performances,the effects of trailing edge jet and traditional Gurney flap on its aerodynamic characteristics are contrastively analyzed by the computational fluid dynamics（CFD）method. Moreover,the improvement effect of different jet outlet widths on aerodynamic performance of airfoil is considered. The results show that the trailing edge jet effectively improves the aerodynamic performance of the airfoil and reduce the drag coefficient at a small angle of attack.The drag reduction effect becomes more obvious with the increase of the momentum coefficient of the jet. And the trailing edge jet effectively reduce the drag increment introduced by gurney flaps and increase the lift-drag ratio of airfoil. When the jet momentum coefficient is constant,the lift-drag ratio and torque coefficient of the trailing edge jet airfoil decrease with the increase of the jet outlet width. When the jet velocity is constant,the aerodynamic characteristics of the airfoil are obviously improved with the increase of the jet outlet width.