The theoretical model of torsion-SARIB vibration isolation system is established, and the dynamic characteristics are analyzed by theory and simulation methods. The dynamics equations of plane torsion-SARIB are derived by the Lagrange method, and the spatial torsion-SARIB is simulated by the multi-body dynamics theory. The comparison between torsion-SARIB and cantilever beam SARIB indicates that torsion-SARIB has low space requirement and simple structure. The torsion-SARIB is more useful than the cantilever beam SARIB in the structure design.