The influence of centrifugal force on rotating ring deformation of highspeed gas seal was studied.The force deformation and the force and thermal coupling deformation of the rotating ring of highspeed gas seal considering and ignoring the centrifugal effect were calculated by using ANSYS121.The rotating ring’s total deformation,the axial deformation of seal face and the seal face taper were compared under the two conditions.Results show that force deformation and force and thermal coupling deformation become much smaller when the centrifugal effect is ignored,and the error is between 1648% and 3753%.The influence of centrifugal effect on axial deformation of the rotating ring face is more obvious at outer diameter side.At the same time the centrifugal force makes the average radial taper of the rotating ring face become convergent positive taper from divergent negative taper.The deformation errors are increased gradually along the radial direction when ignoring the centrifugal effect,and are increased with the increasing of rotating speed.The centrifugal effect can’t be ignored when calculating force deformation and force and thermal coupling deformation under the condition of high rotating speed.