In the alignment calculation process for propulsion shafting systems equipped with shaft-mounted generators, the unbalanced magnetic pull (UMP) is often overlooked, leading to deviations and reduced accuracy in the alignment results. To investigate the influence of the UMP of a shaft-mounted generator on the dynamic alignment of a propulsion shafting system, a finite element model for shafting alignment was established based on a simplified modeling principle. Dynamic alignment analyses were conducted under various conditions: without a shaft-mounted generator, with a shaft-mounted generator but without considering UMP, and with a shaft-mounted generator while considering different UMP values. A comparative analysis of the calculation results was performed. The results demonstrate that the UMP of the shaft-mounted generator affects the shaft deflection, stress, and the load on adjacent bearings. The research findings provide valuable guidance and reference for the accurate alignment calculation of propulsion shafting systems equipped with shaft-mounted generators.