Abstract: The dynamic simulation of aerospace rugged computer case plays an important role in product design cycle. It is helpful not only in seeking optimum solution for product, but also efficient in shortening the research cycle, reducing cost and insuring the product quality. In this paper, the famous FEM software ANSYS has been used. Modal analysis, transient analysis of response of half-sin-shock and PSD analysis of a computer's case has been studied. Then the simulation result was compared with experimental data. It verified the reasonability of the simplified model and the boundary condition used in analysis.