In order to appropriately deal with the connection problems in kinetic analysis such as shell-beam-bar, superposition plates, beam axis-spring, shell-spring, shell-solid connections, et al, in high speed railway's slab track, Timoshenko's shell theory and direct introduction method were applied to establish multi-point constraint equations and the calculation model of the composite slab track. In the composite structure, to solve different type elements' revision to the composite structure's total matrix caused by the elements' offset connections, the multi-point constraint equations on the basis of both the linear hypothesis in shell theory and eccentricity relations among relative nodes pairs in the composite structure were introduced to Galerkin weak form. The reliability of the FEM model on the basis of Timoshenko's shell theory and direct introduction method was proved by the comparison between numerical analysis and real measured results, and meanwhile, the model produces good connections among different layers in the structure, eliminating irrational additional stress generated in conventional methods, which improves the connection problems among different components in FEM analysis.