In order to investigate the steady-state performance,such as gas film stiffness,buoyancy,leakage rate of T-groove cylindrical gas film seal,computational fluid dynamics (CFD) method was used to analyze the influence of changes in the structural parameters of the seal system on the steady-state performance of the system under the working condition of 8 000 r/min.The multivariate nonlinear equations between the seal length,the number of T-groove,the depth of T-groove and the steady-state performance were fitted without changing the film thickness and film eccentricity.The influence degree of each factor was determined by comparing the regression coefficient.The results show that the leakage of the system is most significantly affected by the size of the seal length,and the change of the number and depth of T-groove has no significant effect on the leakage.With the increase of seal length,the air buoyancy increases almost linearly,while the influence of the change of T-groove depth and T-groove number on the buoyancy decreases in turn.The depth of T-groove is the most important factor affecting the gas film stiffness,followed by the number of T-groove,and the seal length has the least effect.