Abstract: The structure of composite pressure vessels with ultra-thin metallic liner was analyzed using the finite element method. In the analysis process, the changes of ply angle and ply thickness along the radius of parallel circles were allowed for in the dome of the geometric model. The composite layer and the liner within the composite pressure vessel were analyzed with laminated plate theory and elastic-plasticity theory in the material model, respectively. Deformation compatibility and non-penetration characteristic between composite layer and liner were considered by introducing contact analysis. The numerical results show that in the work pressure, tension strain is in all the longitudinal direction and compressive strain exists partly in the hoop direction in the dome of the vessel. And plastic deformation occurrs in the liner within composite pressure vessel. After unloading, tension stress exists in composite layer and compressive stress develops in the liner of the vessel. Based on the loaddisplacement curve of maximal displacement point in the liner, buckling deformation of the liner was simulated using a simplified model of the vessel. The experimental data and observed result are in good agreement with the calculated results, which confirms the reliability of the calculated results in this paper.