Abstract: Underwater shield tunnels of oil and gas pipelinesare in the special environment of high water pressure and large burial depth, and their mechanical properties of segment joints are quite different from those of conventional shield tunnels. Herein, a 3D refined model of the segment joint was established based on the finite element software ABAQUS for the Yangtze River shield tunnel project of China-Russia Easten Gas Pipeline. Then, analysis was conducted on the changes in joint deformation characteristics, bolt stress-strain and bending stiffness, especially the overall mechanical response characteristics of joints to the changes of bending performance. The results show that the stress state of the segment joint under the action of bending can be divided into three stages according to the vertical displacement, the opening and the bolt stress-strain of the joint, i.e., slow opening of the joint, the bolt being stressed at the joint opening, and the bolt yielding of the instable joint. Specifically, the stronger the axial force constraint, the later the bolt begins to share the bending action in the slow opening stage of joints. The opening of the joint is sensitive to the axial force, and the proportion of the "slowing section" of the opening growth rate in the bending process of joint decreases gradually with the increase of axial force. For small cross-section shield tunnels with large burial depths and high water pressure, the segment joints are under the action of positive and negative bending moments respectively with unobvious deformation characteristics. However, the positive bending moment has a greater influence on the deformation of the joint bolt under the same axial force. The bending performance of the joints in the Yangtze River shield tunnel of China-Russia Easten Gas Pipeline reflects the stress characteristics of the shield tunnel joints of the oil and gas pipelines, which could provide a reference for the design of the shield tunnel segment structure.