Based on the dry gas seal of the singlespiralangle groove,the mathematical model was established,and the effects of the groove number,spiral angle,groove depth,gas film thickness,ratio of groove and stage,speed on the seal performance were studied using the numerical simulation.The calculated results were in good agreement with the experimental values in the references.By comparing the seal performance parameters such as leakage,flow field pressure distribution and average opening pressure,the seal geometry parameters of the singlespiralangle groove were optimized.Aimed at the problem that there is obvious low pressure area on the suction surface of the spiral groove at the entrance of the singlespiralangle groove,the dry gas seal of the doublespiralangle groove was proposed.The computational results show that the average opening pressure between the doublespiralangle groove and the end face is higher than that of the singlespiralangle groove.Compared with the singlespiralangle groove,the flow separation at the entrance of the doublespiralangle groove suction surface is more obvious,and the dynamic pressure effect in the groove area is also more obvious.The doublespiralangle groove has better sealing performance,and its gas leakage is also lower than that of the singlespiralangle groove.