The utility model relates to an H-shaped safety device for a station cylinder group. A pipe thread is formed in the lower end of a rupture disc joint body, and the upper end of the rupture disc joint body is fixed with a compression nut through a cylindrical thread; a copper gasket, a rupture disc and a shear ring are sequentially pressed between the rupture disc joint body and an inner end face of the compression nut from bottom to top; the compression nut and a welded joint are fixed through a connecting nut; a sealing gasket is arranged between the compression nut and the welded joint; a blow-down pipe is fixed at the upper end of the welded joint; the rupture disc joint body, the copper gasket, the shear ring, the compression nut and the welded joint are provided with axis holes of which diameters are the same or approximate. The H-shaped safety device is compact in structure and convenient to operate, maintain and repair.