Abstract: Based on the background of cross-ocean tunnel in Xiamen metro line two, this paper has conducted force analysis of the shield tunnel segment under the high water pressure and has established beam-spring model considering the joint stiffness. The typical sectional form of shield tunnel structure's stress and deformation were acquired in cross-ocean area. Compared with the stress under low water pressure, this research can draw a conclusion that water pressure's impact on the structure is greater than the earth pressure's. High water pressure can make the structural internal force and deformation increased significantly.As a consequence, segment structure of shield tunnel need to be designed separately. This research result may serve as a theoretical support and construction example for similar excavation engineering projects.