Abstract: Steel tube umbilical cable is consisted of multi-functional-unit spirally-wound composite structure, it is used in connecting the facilities and underwater production system. Based on ANSYS software, 3D finite element numerical model is established using beam element simulation components for the purpose of studying the deformation of the cable under tensile load for its free end in the constraint conditions of twist and non-twist, and comparing the research results with the analytical theory solutions. In the finite element model, it can make up the deficiency of the friction between components by imitating interaction which is completed by setting line-line touch in adjacent components of steel tube umbilical cable and setting Coulomb friction. The computation efficiency is improved greatly. The numerical results agree well with the analytical methods and the finite element method lays the foundation for the deformation law research on other steel tube umbilical cable under bending, squeezing, et al.