Abstract: An apparatus for coupling a rupture disc and a perforated casing is disclosed and pertains to the field of petroleum and gas field development tools. The apparatus includes a coupling body. Axially extended swells are provided at intervals in a circumferential direction on the coupling body. Several radial openings are provided on each swell. A nut is provided in each opening. A rupture disc is provided between one end of the nut and a bottom of the opening. A fixing cap is provided at the other end of the nut. A cavity with particular air pressure is formed by the fixing cap, the nut, and the rupture disc. An upper end of the fixing cap is coated with a self-dissolvable softening film. When the apparatus of the present invention is used to perform perforating or fracturing, structural force of a connected casing is not impaired.