Drilling tool for underground big pipeline shed

The utility model discloses a concentric hole extending sleeve pipe following drill, which is suitable for the strengthening of advanced protection and the construction of big pipe shed in the underground engineering, such as a railway tunnel, etc. The utility model is characterized in that a leading drill 1 and a hole extending drill 2 are designed according to a concentric structure, and the advancing quantity of the leading drill advancing the hole extending drill is determined according to the different compression resisting intensity of rock. The utility model is driven by a double-function impact rotating hydraulic drill. When the drill is drilled, the sleeve pipe is synchronously followed with the drill, when the designed depth is reached, the hole extending drill 2 and the sleeve pipe 5 are maintained in the hole, and other drills exit. The utility model can realize the one-time accomplishment of the processes of drilling the pipe shed hole, installing the sleeve pipe, etc., has the advantages of high construction speed, high work efficiency, 100% hole forming radio, convenient operation, reliability, simple processing, and low cost.