A large space reflector consisting of radial ribs and hoop cables is considered to satisfy rigorous design requirement of a high shape precision as well as lightweight. Due to difficulty of verification of such a large and high-precision space structure by on-ground testing, a simulation-based verification is required. As the first step of establishment of the simulation-based verification, this research investigates the computational accuracy of several nonlinear finite element codes in comparison of numerical solution based on Elastica for the simplified beam model that allows large deformation. Then, sensitivities of deformation with respect to Young's modulus and applied load are investigated.