Hydrostatic bearings are widely exploited in precision machining and high-end equipment. Nonetheless, in scenarios involving high-speed and heavy-duty operations, the oil film possesses excessive heat generation due to shear and extrusion, leading to deformation of the hydrostatic bearing workbench, which affects machining accuracy and thermal stability. In view of the problem, this paper proposes a modification method to reduce the deformation. Hydrostatic bearing workbench under common working conditions is taken as the research object. Considering the viscosity-temperature effect, the variable viscosity fluid simulation of hydrostatic bearing oil film is carried out to investigate the lubrication characteristics. Based on the fluid-solid-thermal interaction method, the deformation characteristics of the hydrostatic bearing workbench are analyzed. According to the anti deformation principle, the guideway surface is modified to control the deformation of the hydrostatic bearing workbench. Finally, the interaction simulation analysis of the workbench after the structural modification shows that the structure modification achieves the expected effect. The oil film temperature is decreased and the bearing capacity is increased. The deformation of hydrostatic bearing workbench is significantly reduced.