Double-cannula drainage tube

The utility model relates to a double-cannula drainage tube which comprises an outer cannula, an inner tube and a flushing tube, wherein the inner tube is arranged in the outer cannula; the flushing tube is integrated with the inner wall of the outer cannula; the front end of the outer cannula is a blind end; the center of the blind end is provided with a drainage hole; a front port of the flushing tube passes through the blind end of the outer cannula; the fronts of the outer cannula and the inner tube are respectively provided with a plurality of drainage holes; the rear of the outer cannula is connected with a seat body which is provided with a water inlet pipe; the water inlet pipe passes through the seat body and is communicated with the flushing tube; the middle of the seat body is provided with a through hole; the inner tube penetrates outside through the through hole; the outer end of the inner tube is provided with a cover body matched with the seat body; the cover body is provided with an air inlet hole and is connected with an air inlet pipe; and the air inlet pipe is communicated with the interior of the cover body and is communicated with a gap between the outer cannula and the inner tube. After the double-cannula drainage tube is adopted, the problem of secondary intubation after the inner tube is blocked in the past can be solved, so that the trouble of doctors can be reduced, and the pain of a patient is relieved.