Gas-residue separating integrated critical pumping device used for coal mine underground hole-drilling

The invention discloses a gas-residue separating integrated critical pumping device used for coal mine underground hole-drilling, which comprises a dust gas catching cylinder and a steam-residue separating box, wherein a residue-discharging port and a spraying water inlet are formed in the dust gas catching cylinder; a gas recycling hole, a residue outlet and a water inlet are formed in the steam-residue separating box; the dust gas catching cylinder comprises an inner tank; one part of the inner tank is inserted into a drilled hole; an outer wall of the inner tank is in sealing connection with an inner wall of the drilled hole under an action of a sealing device; an external end of the inner tank is coaxially and rotatably connected with a rotating head through a bearing arranged in a bearing base; a through hole which passes through a drilling rod is formed in the rotating head; the through hole is coaxial with a pipe hole of the inner tank; the diameter of the through hole is less than the diameter of the