The mathematical model of spiral Angle groove was established, and the influence rules of different groove number, rotating speed, inlet pressure, groove depth and gas film thickness on sealing performance were studied by Fluent. By analyzing and comparing the sealing performance parameters, such as static pressure, opening force, leakage, etc., the optimum geometric structure parameters of single spiral Angle slot are obtained. Aiming at the problem of single helical corner slot, a kind of double helical corner slot dry gas sealing structure is proposed, and the calculation results show that the double helical corner slot can make the aerodynamic separation effect more obvious, and the sealing effect is better when the helical Angle of suction side is larger than that of pressure side. When the two Angle tolerance is 2°, the sealing performance of the spiral Angle slot is better.