Abstract: By taking bump-type gas foil thrust bearing as the research object, a force and deformation model of bump foil and top foil was established by elastic mechanics analysis. The foil structure deformation was calculated and the gas film thickness equation was obtained. On this basis, a fluid-solid coupling model used for calculating the lubrication performance of bump-type gas foil thrust bearings was established with use of Reynolds equation for compressible gas. The established fluid-solid coupling calculation model was tested with specific literature, demonstrating the reliability of the algorithm. With a specific example, the dimensionless gas film pressure distribution, dimensionless gas film thickness distribution and foil structure deformation distribution of the bearing were calculated numerically. The lubrication performance of foil thrust bearing and that of rigid thrust bearing were compared. It was found that the gas film thickness of foil bearing was larger, while the bearing capacity and friction torque were smaller. The influences of bump foil thickness (t_B), half bump length (l), bump radius (R₀), and top foil thickness (t_T) on the lubrication performance of the bearing were studied, and relevant curves were obtained, which showed that bearing capacity and friction torque will increase with the increase of t_B or t_T, and decrease with the increase of l or R₀.