Based on the finite element software ANSYS Workbench， the finite element model of the foil gas bearing movement in compressible fluid medium is established， and the fluid-structure coupling numerical simulation of the bearing movement state is carried out by using the 6DOF dynamic grid calculation method. The influence of different speed and wave foil structure parameters （length ratio， height and thickness of wave foil） on dynamic characteristics of bearing is discussed. The simulation results show that with the increase of rotational speed， the bearing capacity increases， but the stability decreases， and the instability phenome? non is more likely to occur. When the length ratio is between 1~1.5 and the thickness is 0.16 mm， it can not only ensure the high stiffness of the bearing， but also obtain large damping. The height of wave foil is inversely proportional to the dynamic characteris? tics of bearing. The simulation results are compared with the experimental results to verify the correctness and effectiveness of the simulation calculation method. Meanwhile， the research of this paper provides a theoretical basis for optimizing the wave foil struc? ture， improving the dynamic characteristics of bearings and improving the stability.