In order to investigate the influence factor of the aerostatic bearing micro-vibration,the numerical simulation was conducted for the aerostatic bearing clearance flow field,and the relationship between the Reynolds number and the micro-vibration was discussed.Firstly,the transonic flow field structure of the aerostatic bearing clearance was studied under several sets of air supply pressure.Then the influence of Reynolds number on the vortex flow-induced excitation was discussed,and the structure-fluid coupling method was further used to investigate the influence of Reynolds number on the micro-vibration.Finally,the approximate model was established to study the influences of the air pocket volume,orifice diameter,and air film thickness on the maximum Reynolds number in the flow field,i.e.the influence of bearing parameters on vortex flow-induced excitation.The results indicate that the maximum Reynolds number of the flow field can be used to represent the strength of the vortex-induced excitation.However,the micro-vibration also depends on the dynamic performances of the air film-floating facility system.With smaller air pocket volume,the vortex excitation is weakened,and it means that the stability of the aerostatic bearing is improved.The flow mechanism analysis can provide a reference for the aerostatic bearing design to reduce the micro-vibration.