Abstract: The relationship between cable length and tensile forces is deduced using the precise analytical solution of catenary to get a more rigorous mechanics model for cables. Together with the active cable-mesh reflector, an approach to solve the initial equilibrium problem of cable structures is presented based on optimization model to determine the internal stress distribution of cable-mesh with certain geometry and boundary conditions, in which the cable lengths are considered as design variables, and the corresponding constraints are also considered. Detailed analysis procedure of the active cable-mesh reflector is demonstrated with a single cable in a numerical example.