Abstract: Flow field in the T-shaped groove dry gas seal on the 3 D model was built by UG software,meanwhile three dimensional flow field was simulated by Fluent software. Firstly,the classic T groove was analyzed under similar conditions,and the correctness of the simulation calculation method was verified.Then the T-shaped groove was optimized by the method,and calculation were compared with the relevant literature,results shew that the opening force and leakage of new type groove were improved substantially.Finally the relevant geometric parameters of the new type groove were optimized analysis,obtained optimal geometric parameters under different operation parameters.Under different rotational speed and pressure,the optimized T groove parameter selection:α,β value for 40°~ 45°,groove depth h_g value for 4~6 μm.In the constant speed and pressure conditions:m take 6 mm,n take 12 mm.