Ship-ship collision is a very complicated process, different collision parameters will lead to different results. Using ANSYS/LS-DYNA to build a model of ship-ship collision, it studies the side structure collision characteristics at different impact position and initial velocity. Based on the results of calculation, the collision force-displacement curves, energy absorbing-displacement curves, and the damage deformation of side structure are obtained. The simulation results indicate that changing the impact position and initial velocity will obtain the different form and degree deformation. In addition, the critical ship speed of ship shell ruptured is insured, which can offer the theoretical basis for maritime security management.