According to the requirements of material delivery platform in the complex terrain area, the research on the structural design of the composite wing of the tail-sitter electric aircraft was carried out. Based on the load analysis, the structural configuration and lay out designs were studied, and the structural design scheme of the composite wing was proposed. The finite element model of the composite wing was developed and the static strength analyses under different operating conditions were completed. The deformation, structural stress, and Tsai-Wu failure factor distribution of the wing structure were obtained. The structural optimal analysis of the composite wing was performed on the basis of the stepwise optimization strategy with the layer thicknesses and angles as design variables. The optimal results show that the structural mass is reduced by 47.77% under the constraints of structural stiffness and strength, which can provide the important reference for the design and development of the tail-sitter electric aircraft structure.