Abstract: For the power enhancement of horizontal-axis wind turbine blades,the NREL 5 MW blade with 16 winglet profiles were used in numerical simulation of computational fluid dynamics（CFD）. The geometrical parameters in consideration include twist angle,dihedral angle and sweep angle. In order to reduce the overall computational costs,orthogonal tables were established for the parameters above with four per each. Current results showed that,with the optimal configuration the maximum power increases approximately by1.466% and the thrust increases by 1.57%. It is found that twist angle plays the most important role in the torque of wind turbine and so is dihedral angle to thrust. We also analyzed the wake flow behind the blade disk. It is shown that the optimal winglet layout produces a re-distribution of the tip vortex structure of blades and then the improvement of the aerodynamic performance of wind turbine blade is expectable.