Due to the presence of machining errors,the axial runout exists inevitably in the end plane of the bearing.In order to study the effect of the cycle,amplitude and phase of axial runout on the performance of the hydrostatic thrust bearing,by only considering the dominant fundamental frequency harmonic beating and introducing it into the gap change equation of the bearing sealing surface,the model of the thrust bearing end plane was constructed,the variation of oil film thickness was simulated in the sealing surface.The Reynolds equation in the polar coordinate system was solved by the finite difference method,the pressure distribution on the bearing sealing surface was obtained,and the influence of the cycle,amplitude and phase of the fundamental wave on the static characteristics of the thrust hydrostatic bearing was analyzed.The results show that,when the structural parameters remain constant,with the increasing of the rotational speed,the flow rate,the bearing capacity and the dynamic pressure ratio are increased,while the pressure of the hydrostatic chamber is decreased.At the same rotational speed,with the increasing of the cycle,the flow rate is decreased,the pressure of the hydrostatic chamber and the bearing capacity are increased,and the dynamic pressure ratio is firstly increased and then decreased;with the increasing of the amplitudes,the flow rate and the dynamic pressure ratio are increased,the pressure of the hydrostatic chamber and the bearing capacity are decreased;with the increasing of the phase,the flow rate is decreased after the first increase and then increased,the pressure of the hydrostatic chamber is increased after the first reduce and then decreased,the bearing capacity and dynamic pressure ratio are decreased after the increase