Construction method of concrete engineering deformation joint vertical water stop cavity mold

The invention discloses a construction method of a concrete engineering deformation joint vertical water stop cavity mold. The cavity mold comprises a water stop piece, a skeleton and an airbag; the airbag is connected with the skeleton, and is arranged on the outer side of the skeleton; when the cavity mold is applied, the water stop piece is partially embedded in a first-stage concrete section; the skeleton is connected with the water stop piece; the airbag is filled with gas with a preset pressure; and after second-stage concrete is primarily condensed, when the air pressure in the airbag is released, and after the skeleton and the airbag are removed, a semicircular cavity for injecting fused asphalt is formed in the second-stage concrete. The cavity mold is simple in structure and easy to assemble and use, can effectively solve the extension joint seepage problem caused by nonuniform stratum settlement or diastrophism of the hydraulic engineering, can be recycled, and is low in cost.