The invention discloses a rotatably-connected medical oxygen inhalation tube device capable of automatically sealing and closing. The rotatably-connected medical oxygen inhalation tube device capableof automatically sealing and closing comprises an oxygen catheter body, a branch air suction tube body and a three-way connecting tube. One end of the oxygen catheter body is matched and connected with an oxygen supply source for supplying oxygen, and the other end is fixedly provided with a sealing connector. The three-way connecting tube comprises a first connecting branched tube, a second connecting branched tube and a third connecting branched tube. Two ends of the branch air suction tube body are cooperatively and fixedly connected to the first and second connecting branched tubes of thethree-way connecting tube. The rotatably-connected medical oxygen inhalation tube device is capable of realizing the detachable connection of the branch air suction tube body and the oxygen catheter body, and is more safe and sanitary. The branch air suction tube body can be conveniently folded for protection without pollution while the branch air suction tube body is not used, and the limited space of a sickroom is not occupied. In addition, the automatic closed airtightness connection between the branch air suction tube body and the oxygen catheter body can be realized, the use is more convenient and practical, and the treatment for a patient is more convenient.