Abstract: In order to improve sealing performance of the cylindrical spiral groove model,Fluent software is employed to numerically simulate three models:cylindrical spiral groove,T-groove and slotted groove.Three grooved cylinder air film seals are investigated under three variable working conditions:rotational speed,differential pressure and eccentricity.The results of the study show,under different working conditions and structural parameters,the sealing effect of the spiral groove structure is better than that of the T-groove structure and the slotted structure,and the dynamic pressure effect of the spiral groove structure is superior.Both the rotational speed and pressure difference have a significant influence on the sealing performance of the spiral groove whereas the eccentricity has small impact.When the rotational speed reaches 20 000～30 000 r/min,the pressure difference is 0.4～0.7 MPa,and the eccentricity is approximately 0.5,all the sealing performance parameters of the spiral groove cylinder air film seal reach comparatively satisfactory levels.This study may provide guidance for the future research and optimization of cylinder gas film sealing structures.