Fly pipe equipment for underground construction

The invention discloses fly pipe equipment for underground construction, which comprises a fixed sleeve, a fly pipe retaining device and a fixed sleeve, a threaded layer is arranged at the bottom end of the inner side of the fixed sleeve, the fly pipe retaining device is arranged at the bottom end of the fixed sleeve, an L-shaped moving groove is formed in the side wall of the front end of the fixed sleeve, and the fixed sleeve is arranged in the L-shaped moving groove. Movable grooves are formed in the top end and the bottom end in the L-shaped movable groove, a mounting seat is arranged on the inner wall of the top end of the fixed sleeve, a fixed sleeve is arranged at the top end of the mounting seat, a rotating shaft is arranged on the inner wall of the fly pipe retaining device through a bearing, and a barb is arranged at one end of the rotating shaft; according to the technical scheme, the fly pipe retaining device is positioned below the fixed sleeve, the fly pipe retaining device is mainly composed of