The optimization design problem of vibration isolation and shock resistance system is studied in consideration of acoustical concealment performance and life-force of ships. The weakness of design method based on continuity is pointed out and combination optimal design method is brought forward. Then the limiting performance of shock isolation system is analyzed and two realization methods are discussed. One method is to adopt linear stiffness component with large damping. The other method is to use multiple linear stiffness components without damping. Simulation results showed that the optimal loss factor is still 0.4 when the stiffness of shock bumper is much larger than that of vibration isolator, just the same with that suffering from only shock loads. Simulation results also showed that limiting performance can be achieved by configuration optimal design using multiple linear components. The two discussed methods can be used to direct engineering application.