Abstract: In order to further develop the design potential of different material space layout and realize lightweight design,a topology optimization method of multi-phase materials for wind turbine blades combining ICM method and SQP algorithm is proposed. The topology optimization mathematical model is established,which takes the density of structural element as design variable,the minimum weight as the objective function and the displacement as the constraint. The algorithm program is written in Matlab and the problems are solved interactively with Abaqus software,and the optimized space layout of the composite fiber and soft sandwich material of the blads is obtained. Taking 1.5 MW blade as an example,the weight of optimized blade is reduced,and the properties are improved. Based on equivalent design method,the strength of the redesigned ofter partial adjustment meets the design requirements. The effectiveness and feasibility of the method are verified.