<p>In shaft-bearing systems, manufacturing errors in parts result in variable ring misalignments during rotation, influenced by the coupling effect of assembly deviations as well as internal and external forces. In addition, with the trend toward lightweight and compact structure design in shaft-bearing system, the multi-datum geometric tolerances are widely used, which may generate some partial parallel chains. Neglected these factors may lead to large differences in assembly deviation, and further affect the ring misalignment during rotation. To solve these problems, the quasi-static ring misalignment prediction model during rotation is established for shaft-bearing system with considering the coupling effect of assembly deviation, internal and external forces. Firstly, the formulation of ring misalignment in shaft-bearing system considering the multi-datum geometric tolerancses is introduced, and the solution to the partial parallel chains caused by the multi-datum geometric tolerances is proposed. Secondly, considering the assembly deviation, the quasi-static ring misalignment model due to internal and external loads is established to predict the changes of ring misalignment during rotation for shaft-bearing system. Finally, the experiments are conducted to verify the proposed solution of partial parallel chains caused by the multi-datum geometric tolerances, and the maximum error percentage between the solution and experiment is 11.8%. In addition, an application is given to demonstrate the quasi-static ring misalignment prediction model, and the influences of assembly deviation and structure parameters on the quasi-static ring misalignment errors during rotation are analyzed.</p> Graphic Abstract <p></p>