Based on the traditional spiral groove,a new spiral groove structure was proposed,in which a short groove with different root radius was arranged on the lee side of the traditional spiral groove,and the depth of the two grooves was equal,thus forming a new spiral groove structure with longer root.The geometrical models of the traditional spiral groove and the new spiral groove were established,and the numerical simulation of the two grooves was carried out by using ANSYS simulation software.The results show that the dry gas sealing performances of the new spiral groove are better than that of the traditional spiral groove,such as opening force,leakage and stiffness.The stress and deformation of the seal ring under the convection-solid coupling were analyzed,and the differences of the fluid-solid coupling stress and deformation of the two kinds of seal rings under the same operating parameters were compared.It is found that the maximum stress and deformation of the dynamic and static rings of the two grooves increase with the increase of the rotating speed and inlet pressure,and the maximum stress and deformation of dynamic ring is always greater than those of the static ring,and the maximum stress and deformation of the new spiral groove is always greater than those of the traditional spiral groove.