Wind turbine aerodynamic-mistuning phenomenon during the operation may cause great harm. This article is based on sliding mesh technique of three dimensional Unsteady CFD method,taking NREL Phase VI wind turbine as an e xample,study the pneumatic performance of wind turbine under the axial-flow condition,and compare with the expe rimental data.After validate the accuracy of the method,according to the effect of yaw and wind shear on the wind tu rbine aerodynamic mistuning ,researched have been conducted: In a wind shear condition, the aerodynamic performance after the blade rotating one circle have been calculated in the different wind profile index.Because of the shear wind velocity, Airfoil load and flow parameters fluctuate approximately like the patterm of cyclical cosine function with the change of azimuth.And with wind profiles index and spanwise position increases, impulse amplitudes have been also increased;Under the circumstances of the constant wind speed and variable yaw angle , The aerodynamic power decreases with the increase of the yaw angle There are also some big differences at different azimuth angle of blade section.