The invention provides a device for filtering flow and releasing pressure on a water inrush borehole and sleeving tube in the hole for grouting, fixing tube and blocking and a tube-fixing and blocking method thereof. The device comprises an outer tube, wherein the outer tube is provided with a dislocation position; a hole wall filtering and pressure-releasing mechanism is arranged at the pipe orifice of the outer tube; an inner tube is inserted into the outer tube through a charging hole of the hole wall filtering and pressure-releasing mechanism, so that the dislocation position is positioned between the two ends of the inner tube; a charging tube is fixed to the charging hole of the hole wall filtering and pressure-releasing mechanism; an orifice gate valve is fixed between the charging tube and the hole wall filtering and pressure-releasing mechanism. Compared with the prior art, the device has the advantages that the small-aperture inner tube is arranged in the outer tube towards a position below the tube-sleeving dislocation position, slurry is injected into the hole through the inner tube, the slurry permeates through a breaking position of the casing, blocks a water outlet gap channel on a roadway floor, flows into a gap between the inner tube and the outer tube to fix the tubes by filling, and blocks a water-containing layer to realize water blocking on the roadway floor and filling between the inner tube and the outer tube, so that the aims of fixing the inner tube and the outer tube, blocking the borehole and treating the effluent from the roadway floor are fulfilled.