A structure topology optimization method based on material-field reduced series expansion is disclosed. A bounded material field that takes correlation into consideration is defined, the bounded material field is transmitted into a linear combination of a series of undetermined coefficients using a spectral decomposition method, these undetermined coefficients are used as design variables, an optimization model is built based on an element density interpolation model, the topology optimization problem is solved using a gradient-based or gradient-free algorithm, and then a topology configuration with clear boundaries is obtained efficiently. The method can substantially reduce the number of design variables in density method-based topology optimization, and has the natural advantage of completely avoiding the problems of mesh dependency and checkerboard patterns.