It is a complex but important issue to have a shower for the sailors in a luxury passenger liner whose working and living staff are all to be held in a closed environment. It is hard to decide what kind of showering mode can satisfy the sailors’ showering need, as well as using discrete event theory to handle it because of the mass of people and their behavior’s randomicity. A method based on the theory of discrete event to simulate the showering mode in the ship has been brought out by using the software of QUEST, and the design of the bath system of the ship has been proved to be with usability after simulations. What factors and how they affect the performance of the showering system have been found. At last, an implementation suggestion has been brought forward.