A tensioning method for a tensegrity keel is provided. The method includes the step of determining target values at an attainment of tensegrity. An outline of the integral keel is formed. A middle stiffening ring is tensioned through stretching a hub shaft, thereby attaining a self-equilibrium state. Telescopic rods are provided between stiffening rings and central trusses so that the stiffening rings and the central trusses are connected together. Longitudinal ties are mounted and constraints on bisection points and the central trusses are released and the integral keel is tensioned by stretching the telescopic rods, thereby introducing tension to the longitudinal ties. The lateral stiffening rings are tensioned by stretching the hub shaft, thereby attaining a self-equilibrium state. Adjustments are made using iterative methods so that target values at the attainment of tensegrity will be reached.