In order to study the influence of sloshing phenomenon of ballast tank on bulkhead structural strength of aquaculture vessels, the Smoothed Particle Hydrodynamics (SPH) method was used to simulate the slight sloshing and violent sloshing of ballast tank under rolling excitation. The influence of particle truncation error on or near the solid wall boundary of SPH method was solved by introducing dynamic boundary particle method. The simulation results of the two processing methods of dynamic boundary particles were validated by comparing with related literatures. The results show that the method used in this paper is reliable and effective, and is suitable for simulating the rolling and breaking of free surface during ballast tank sloshing. For slight tank sloshing, the boundary particle fixed method has higher calculation accuracy than the boundary particle motion method; both the boundary particle motion method and the fixed boundary particle method can effectively simulate the violent tank sloshing phenomenon. The results of this study can provide a reference for the numerical simulation of sloshing in the culture tanks of aquaculture vessels.