In order to study the influence of longitudinal joints on the convergence deformation of shield tunnel lining, the ratio of the convergence deformation caused by longitudinal joint rotation to the overall convergence deformation was introduced as an index to quantify the impacts of longitudinal joints on convergence deformation. On the basis of the initial assembling angle of longitudinal joints and the geometric recurrence relationship between joints, a simple algorithm for calculating convergence deformation caused by longitudinal joints in shield tunnel lining was proposed. First, the effectiveness of the proposed simple algorithm was verified by comparing with the results of existing multi-scale hybrid analysis. Then, with the results of full-scale loading test and 3D numerical simulation, the simple algorithm was applied to analyze the changes in the influence of longitudinal joints considering factors such as persistent/staggered fabrication, joint position, lining longitudinal force, and alternating loading and unloading. Results show that for persistently fabricated lining, the convergence deformation caused by joint rotation played a dominant role in the overall deformation, while staggered fabrication significantly reduced the influence of longitudinal joint rotation on the convergence deformation. The closer the joint was located to the maximum bending moment area, the greater the influence of longitudinal joint on the convergence deformation was. The increase in the longitudinal force enhanced the integrity of the segment, so the joint rotation-induced convergence deformation decreased with increasing longitudinal force. During the unloading process after loading, the influence of the longitudinal joint increased as the elastic self-deformation of segments could be recovered but the joint rotation-induced deformation retained. The research findings can provide useful guidance on segment structure design and tunnel health status evaluation in practical engineering.