Abstract: Considering the effect of the deformation of wind turbine blades on the surrounding flow field,the particle image velocimetry（PIV）method is used to collect the surrounding flow field information of two horizontal axis wind turbine blades with the same material but different aileron shapes,namely glass polyester（blade Ⅰ）and glass polyester filled with foam（blade Ⅱ）,so as to analyze the flow field data at different test sections. The research results show that compared with blades Ⅰ,the average vorticity,the area of the recirculation zone and the time-averaged velocity of the blade Ⅱ are larger,and the axial Reynolds stress is smaller under the same working conditions. With the increase of the relative axial distance,the fluctuation of the time-averaged velocity in the relative height direction decreases,and the influence of the material on the axial Reynolds stress gradually weakens. Under the test conditions,the influence of the blade material on the characteristics of the surrounding flow field is greater than the influence of the tip speed ratio on it,and it has a tendency to increase in the radial direction.