The current topology optimization and structural parameter design of large wind turbine blades are disconnected,resulting in topology optimization results cannot effectively guide the design of blade structural parameters.For this problem,Sandia 5 MW blade was studied by topology optimization method to find the optimal material distribution of blades under multiple working conditions.Three main structural parameters,including blade main beam width,main beam offset and web offset angle (main girder dislocation angle) were extracted to analyze the impact of each parameter on blade performance.The results show that the main beam is the widest at about 1/3 blade root,and then gradually decreases along the blade length;about 5° web offset angle can improve the overall first-order natural frequency and blade displacement performance;at the same time,the first-order natural frequency of the blade is mainly affected by the stiffness in the flap direction.