In order to further improve the static performance of hydrostatic gas bearing,a composite throttling hydrostatic gas bearing was proposed based on ordinary orifice throttling and combined with surface circumferential and radial groove throttling,so as to fully utilize the advantages of the two throttling methods and make the hydrostatic gas bearing have better bearing capacity and stiffness.Fluent was used to calculate the flow field parameters in the bearing and analyze the flow field characteristics.The bearing capacity and stiffness between the composite throttle aerostatic bearing and the ordinary orifice throttle bearing were compared and analyzed,and the effects of orifice parameters and surface groove parameters on the static characteristics of the composite throttle aerostatic bearing were studied.The results show that the composite throttle aerostatic bearing has a significant effect on improving the bearing capacity and stiffness in a certain range of film thickness.Composite throttling has a better pressure equalization effect due to the presence of secondary throttling with surface grooves.Increasing the number,diameter,and distribution radius of throttle holes,as well as increasing the length,width,and depth of surface grooves when the gas film thickness is small,are beneficial for increasing the bearing capacity.When the gas film thickness is small,increasing the number and reducing the diameter of throttle holes,and increasing the length and width and reducing the depth of surface grooves,are beneficial for increasing bearing stiffness.