Aiming at the problem that the static performance of the closed rectangular hydrostatic air-bearing guide is poor and the mainstream optimization design method is time-consuming， this paper quickly optimized the design of a closed rectangular hydrostatic air-bearing. First of all， the simulation model of rectangular air-bearing was constructed by using FLUENT software， and the simulation calculation was carried out by using this model to analyze the effects of different throttle hole distribution positions and the number of throttle holes on the static performance of rectangular air-bearing， and determine the optimal throttle hole distribution position and the number of throttle holes. Then the curves of the throttle structural parameters and the bearing capacity， stiffness and air consumption of the air-bearing were analytically fitted by the response surface optimization design method， and the optimal design parameters of the rectangular air-bearing were quickly obtained by combining with the response surface curve diagram. The results show that the optimized structural parameters of the bearing capacity and stiffness are increased by 11.27% and 80% respectively， and the gas consumption is reduced by 15.86%. Finally， experimental verification is carried out， and the curves of the experimental test values and simulation values are basically fitted consistently， which demonstrates the reliability and accuracy of the method in the design of structural parameters of the gas-static bearing. This paper has important reference value for the rapid design optimization of rectangular hydrostatic bearings.