In order to further comprehensively calculate the longitudinal internal force and deformation of long immersed tunnel, and to ensure the joints′ watertightness, the calculation models for longitudinal static analysis of immersed tunnel and some problems, i.e. the joint mechanics, selection of GINA gasket with its and watertightness verification and relationship among longitudinal settlement difference, longitudinal bending moment and shear force, etc., are discussed. And then the simple and efficient elastic foundation beam calculation model and joint simulation methods are summarized; the 3D shell models with stratumstructure mode and forced displacement method are put forward for supplementary detailed analysis. Finally, it is pointed out that the curvature and curvature variation rate of the longitudinal settlement curve of the tunnel affect respectively the longitudinal bending moment and shear force of the structure; and it is given that how the selection work and watertightness verification of water seal cooperate with longitudinal calculation of tunnel structure.