The bearing capacity and stiffness are the key factors to measure the performance of air bearing spindles,which are directly affected by the throttling method.However,the influence of axial arrangement of the orifice on the supporting performance of the aerostatic gas bearing is lack of in-depth investigation at present.In order to study the influence of axial arrangement of orifice on the characteristics of aerostatic gas bearing,three typical throttling structures were designed,including two rows of holes,middle exhaust four-row-hole and middle non-exhaust four-row-hole.The mathematical model of gas film force of aerostatic gas bearing was established based on the Reynolds equation,and the influence of the shaft speed and the axial arrangement of the orifices on the bearing capacity and stiffness was analyzed.The accuracy of the model was verified through experiments.The results show that,in the low-speed stage,the bearing capacity and stiffness of the middle exhaust four-row-hole structure bearing is the largest,which is suitable for the application of low-speed and heavy-load working condition.In the high-speed stage,the bearing capacity and stiffness of the middle non-exhaust four-row-hole structure bearing are the largest,and its dynamic pressure effect is obviously improved,especially the bearing with large length diameter ratio is suitable for high-speed working condition.The bearing of two rows of holes has the above two advantages and is suitable for balanced performance application.The accuracy of the model was verified through experiments,and the research results have the guiding significance for the selection and design of aerostatic gas bearings in different application requirements.