The displacement impedance performance directly reflects the capability of the aerostatic bearing to resist the external dynamic load,and it should be optimized in design of bearing dynamic performances to reduce the pneumatic hammering vibration.To improve the bearing dynamic performances and reduce the pneumatic hammering vibration,the displacement impedance of the air film-floating facility system was studied.Using numerical simulation method and applying the dynamic mesh technology to calculate the displacement impedance,the influence mechanisms of the structural and operating parameters on the displacement impedance were discussed for the aerostatic bearing with multi-orifice type restrictor.Based on the radial basis function neural network model,an approximate analysis model of displacement impedance expressed by bearing parameters was established,and the influence of bearing parameters on displacement impedance was compared and discussed using PARETO analysis.The optimization model was established,the frequency among the pneumatic hammering vibration range was considered,and the displacement impedance was optimized with the given bearing load to reduce the pneumatic hammering vibration.The results indicate that due to the squeeze film effect,the excitation frequency has the largest influence on the displacement impedance.The displacement impedance increases dramatically with the increase of excitation frequency. Therefore,the bearing can resist the dynamic load with high frequencies effectively, and it is important to improve the displacement impedance with low frequency excitation.The orifice diameter,air film thickness and the air supply pressure have larger influence on displacement impedance than the air pocket sizes and the orifice position.The analysis and optimization process can give a reference for the bearing design in engineering.