Abstract: Useing the NACA 4415 horizontal-axis wind turbine as a case study and through the numerical simulation calculation method of fluid-solid coupling,considering the aerodynamic load and centrifugal load as well as their coupling effect,the maximum chord length,middle chord length,aerodynamic center line spanwise direction and the position of the maximum stress point are selected to analyze the stress characteristics of wind turbine blade under different working conditions in this paper.The study indicates that under aerodynamic load,the windward surface stress at the same chord length of the blade is less than the leeward stress,which increases with the tip speed ratio and the inflow wind speed.As the tip speed ratio increases,the maximum stress point position extends outward along the wingspan and near the leading edge of the blade.Under the action of centrifugal load,the windward surface stress at the same chord length of the blade is greater than the leeward surface stress,which increases with the tip speed ratio,the maximum stress point is at the maximum chord length of the blade（9.93 mm,10.80 mm,-126.33 mm）.Under the coupling action,the windward surface stress at the same chord length of the blade is greater than the leeward surface stress,which increases with the increase of the tip speed ratio and the inflow wind speed.Also,the windward surface stress is in turn greater than the stress generated by aerodynamic load and centrifugal load.The maximum stress point is at the maximum chord length of the blade.The simulation results have important theoretical significance and reference value for the selection and optimization design of wind turbine airfoil.