[Objectives] Aiming at the vibration control problem, this paper put forward a design approach of longitudinal two-stage vibration isolation technology of ship propeller-shaft system. [Methods] The vibration mathematical model of ship propeller-shaft longitudinal two-stage vibration isolation system is established. The influence of mass ratio, stiffness ratio and damping ratio of two-stage vibration isolation system is studied. The design is optimized taking a ship propeller-shaft system as an example.[Results]The results show that the ship propeller-shaft longitudinal two-stage vibration isolation system which is optimized has better isolation effect than the single-stage vibration isolation system.[Conclusions] The research results have important reference value for ship propeller-shaft longitudinal vibration isolation design.