Abstract: Spiral groove dry gas seal is a new type,non-contact mechanical seal, which has many advantages such as small leakage, little surface abrasion, low power loss, long service life and high reliability.Utilizing the finite element method, the flow of the gas between the spiral groove dry gas seal faces was investigated by numerical simulation.The pressure distribution of the gas film was obtained.The main seal performance parameters, such as open force, friction force of the face, frictional power loss, axial stiffness and leakage rate were calculated.The influence of the operation conditions and the spiral groove’s geometric parameters on seal performance was also analyzed.The research results provided valuable reference for design of the spiral groove dry gas seal.