Abstract: Hydrostatic gas bearing mainly provides radial support for pistons of Free-piston Stirling generators,which is a key technology needed to be broken.Based on the introduction of the principle and basic structure of gas bearing,combined with COMOSL Multiphysics and MATLAB software,the effects of relative intake pressure,bearing geometry and axial movement of the piston on bearing performance were analyzed.The results showed that the relative intake pressure and the number of orifices are positively correlated with the capacity of the bearing;With the increase of the seal gap and the diameter of the orifices,the load capacity increases firstly and then decreases.In addition,the axial movement of the piston also has a certain influence on the performance of hydrostatic gas bearing.