The invention relates to a device and method for rapidly taking out a metal sealing ring from a small duct. The device comprises a convex step combination and a concave step combination. The convex step combination consists of a tool coat nut, an ejector shaft, a pull shaft and a pull plate combination, and the concave step combination consists of an ejector sleeve, a pull sleeve and a pull platecombination. Each pull plate combination comprises an upper pressing block, a lower pressing block, a butterfly nut and a stud. When the metal sealing ring is inlaid in a female end of a joint of thesmall duct, the convex step combination is used for taking out the metal sealing ring in the joint of the duct; and when the metal sealing ring is inlaid in a male end of the joint of the small duct,the concave step combination is used for taking out the metal sealing ring in the joint of the duct. By the device, the metal sealing ring which is inlaid in any of the female end and the male end ofthe joint of the small duct can be taken out rapidly, the metal sealing ring can be nondestructively separated from the device, production efficiency of installation and maintenance of the small ductis improved, quality risks are reduced, and potential quality hazards are eliminated.