The parameterized model of cylinder gas film seal was established,and the effect of cylindrical structure on sealing performance was studied.The results show that,with the increasing of eccentricity ratio,the gas film lift pressure and the maximum pressure are all increased,and the best fluid dynamic pressure effect is got when the eccentricity ratio is 07.The influence of rotate rate on cylindrical gas film seal properties was studied under the eccentricity ratio of 07.The results show there is small fluid dynamic pressure effect at low rotate speed,and with the increasing of rotate speed,the fluid dynamic pressure effect is enhanced.When the rotate speed reaches a certain value,the fluid dynamic pressure effect tends to be stable.