In order to study the influence of bearing parameters on stiffness and damping characteristics of the air film,the characteristics of the dynamic load of the air film when it is subjected to the external displacement excitation were investigated by numerical simulation based on the dynamic grid method,and the carrying capacity,stiffness and damping were calculated.Considering the air film thickness,air pocket sizes,orifice diameter,air supply pressure and the excitation parameters,the orthogonal arrays were established based on the orthogonal experimental design theory.The sample points were calculated,and the mathematics model of the bearing carrying capacity,stiffness and damping with respect to bearing parameters was established based on the radial basis functions method.The influences of pocket sizes on mechanical performances were investigated based on the approximate model.The results indicate that due to the squeezefilm effect,the increase of the excitation frequency can increase the stiffness and decrease the damping.With smaller gas volume of the bearing clearance,the increase of the stiffness with excitation frequency becomes faster.