Abstract: In order to obtain a refined and rational structural design method of large-section shield tunnel, the structure selection and structure parameters are analyzed based on a large-section sea-crossing shield tunnel. The selection method of segment structure is analyzed in terms of segment erection method and segmentation, segment connection method and segment material; the numerical simulation calculation methods of segment cross-section and tunnel longitudinal structure and its applicability are analyzed in terms of selection of calculation model, determination of calculation conditions and loads, selection of parameters and calculation results. The results show that the internal force distributions in the calculation of segment cross-section by the beam-spring model or homogeneous ring model are not the same, the design should consider the main calculation result while the latter should be used for recheck in actual design; it is easy to produce large longitudinal bending moment and shear between segment rings of the shield tunnel located in the place where the foundation changes violently, and it can be solve by setting deformation joints, crushing hard rock block and so on.