Gas well casing pressure reinjection yield increasing device

The utility model provides a gas well casing pressure reinjection yield increasing device which comprises a main body of an outer casing pipe, a sealing ring plate is arranged at one end of the main body, a sealing ring groove is formed in the sealing ring plate, a sleeving ring plate is fixedly connected to the position, on the outer wall of the main body, of the outer portion of the sealing ring plate, and a sealing ring groove is formed in the sleeving ring plate. A plurality of spacing ring plates are evenly arranged on the inner wall of the sleeving ring plate, clamping grooves are formed in the middles of the spacing ring plates, a plurality of clamping and locking grooves are evenly formed in the positions, between the spacing ring plates, of the inner wall of the main body, locking grooves are formed in the bottoms of the clamping and locking grooves, and locking grooves are formed in the two sides of each locking groove. A sealing connecting plate matched with the sealing ring groove is arranged at t