In order to accurately analyze the structural integrity of vertical launching system pressure chamber, missile vertical launching system in the pressure chamber were structural integrity analysis. Introduced the missile vertical launching system, the flow field in the vertical launching system was calculated by the method of numerical calculation, will get the pressure distribution is imported into ANSYS structure analysis software calculation results, and from three aspects of stress, strain and deformation, the structure of pressure chamber is analyzed. The result shows that the pressure chamber has good performance after 8 launches the stress and deformation mainly distributed on the top of deflector. The simulation results can provide reference for life assessment of pressure chamber.