The invention discloses a Casales quick-opening sealing device, comprising a flat cover, a threaded sleeve and a barrel end part, wherein the upper thread section and the lower thread section of the threaded sleeve are respectively and rotationally connected with the flat cover and the barrel end part, a compression ring and a sealing gasket are arranged in the clearance between the flat cover and the barrel end part, and a set of hydraulic cylinder is arranged on the flat cover and internally provided with a disc spring; and the top end of the piston rod of the hydraulic cylinder correspondsto the compression ring. By utilizing a hydraulic-disc spring system to replace a puller bolt in a norm, the sealing is realized by compressing the sealing gasket through pushing the compressing ringvia hydraulic force. The invention can ensure that the automatic control on the opening and closing of the bottom cover of a large-sized high-temperature coke tower is realized, which is safe and reliable, shortens the opening and closing time of the bottom cover, lightens the labor intensity of operators, and guarantees the safety. The invention is also suitable to the quick-opening/closing mechanisms of other high-temperature high-pressure containers.