Abstract: The optimization of warship broadside defensive structures is of great importance for the anti-shock capability of the sandwich cabin, which is widely adopted abroad. With MSC.Dytran, this paper studies the dynamic response and energy absorbing characteristics of the sandwich cabin, analyzes the influence of the four size parameters (the thickness of the front cabin wall, back cabin wall, arc shaft separator, and radius) on the deformation and energy absorbing characteristics of sandwich cabins. Based on the above analysis, the fitting formula in calculating the deflection of center points on the front and back cabin, the max plastic strain, and the distortion energy of the front cabin wall and core constructure is proposed respectively. The results show that when the four parameters change within a certain range, the discrepancy of fitting results and simulation results is below 10%. In brief, the research results provide sound reference for the design of sandwich cabins.