Abstract: The thermal deformation of the friction pair of hydrostatic bearing of heavy vertical lathe has great influence on the shape of oil film under the conditions of high speed and heavy load. The thermal deformation will result in great changes of the oil flow state, basic assumption and boundary conditions. Thus, it is difficult to use the theoretical lubrication performance formula to predict precisely the lubrication characteristics of the oil film. To solve this key problem, the thermal deformation of rotating workbench and base is simulated based on fluid-structure interaction method, and the law of thermal deformation distribution is revealed. The relationship between the thermal deformation of hydrostatic thrust bearing and rotational speed of the workbench is established. A model to predict the lubrication performance of oil film is proposed considering the thermal deformation. A test rig is established and experiments are carried out. The experiment results are basically in agreement with the simulation results. This work may provide reasonable theoretical basis for design of heat dissipation structure, lubrication and solving deformation problem of hydrostatic thrust bearing.