The invention relates to a cylinder structure applying a step prestress. The cylinder structure comprises a cylinder body and a plurality of prestress structures, the pre-stress structure is sequentially added to the outer diameter of the cylinder body according to the axial size, and the arrangement of the prestress structure is completely distributed according to the load of the axial size of the cylinder body. The cylinder structure has the beneficial effects that different prestress is applied to the cylinder bodies of different pressure intensity sections through different prestress structures, so that the cylinder structures of different axial size sections can be formed, the overall radial size change tends to be stable after the internal pressurization is borne, the sealing of theinner structure of the barrel is facilitated, and the sealing effect of the inner structure of the barrel is improved.