The utility model provides a small cross section is porous, and guan xuan spouts drilling tool, this small cross section is porous, and guan xuan spouts drilling tool's external diameter is less than 100mm. Better, small cross section is porous, and guan xuan spouts drilling tool's external diameter is 90mm. This small cross section is porous, and guan xuan spouts drilling tool spouts the drill bit soon and starches coaxial nozzle including spouting drill bit body gentleness soon including spouting the drill bit soon, and the coaxial nozzle setting of gas thick liquid is in the side of spouting the drill bit body soon, and the axis of the coaxial nozzle of gas thick liquid and the axis slope setting of spouting the drill bit body are soon spouted the drill bit body soon and is had first and second tip, and the coaxial nozzle of gas thick liquid inclines towards the second end. Preferably, the axis of the coaxial nozzle of gas thick liquid becomes 70 contained angle settings with the axis that spouts the drill bit body soon. The utility model discloses a small cross section is porous, and guan xuan spouts drilling tool can be used for the construction ground internal pressure in subway tunnel by -pass controllable and do not have mud and discharge high pressure injection grouting foundation stabilization, and enable the outer lonely face surrounding soil in tunnel and also consolidated by high pressure injection grouting, design benefit, the structure is succinct, makes portably, just is suitable for extensive popularization and application.