Laryngeal and tracheal stenosis is a common clinical disease, mostly caused by: 1. advanced laryngeal, tracheal, bronchial, thyroid, esophageal or mediastinal tumors; 2. trauma-induced collapse of the tracheal wall; 3. tracheal and bronchial softening disease and other etiologies. The main symptoms are dyspnea and dysphonia, which can be life-threatening in severe cases. In the past, traditional treatment methods included surgical procedures (laryngeal and tracheal reconstruction, sleeve resection and end-to-end anastomosis), stenosis expansion, endoscopic treatment (laser, microwave and high-frequency electric knife), placement of T-tubes, etc.; traditional treatment, which required several iterations, long treatment time and high cost; in some patients, because of severe laryngeal and tracheal stenosis, several surgeries could not remove the tracheal tube, which made the patients lose their labor force. It is no wonder that severe laryngeal and tracheal stenosis has become a problem for clinicians. Advances in medical bioengineering have opened a new page in the treatment of laryngeal and tracheal stenosis. In 1963, the United States Buehler discovered that nickel-titanium alloys (Ni-Ti alloys) have a shape memory effect, and its superior superelasticity is better than stainless steel. Ni-Ti shape memory alloys (NT-SMA) are metallic compounds with nickel content between 54-56%, which exhibit different metal structure phases at different temperatures. At low temperature, it is a monoclinic phase (martensitic phase), and at high temperature, it is a cubic phase (austenitic phase). The former is soft and can be deformed at will, such as straightened flexure; while the latter is rigid and recovers its original shape, and generates a large recovery force during the shape recovery process. nt-sma can be shaped into various desired shapes such as spiral, lattice, etc. at 5000C high temperature, i.e. memory shape; the shaped memory alloy can be deformed at will at 0~40C low temperature; when the temperature rises to 35~400C When the temperature rises to 35~400C, it quickly returns to the original memory shape. The phase change temperature is related to the composition ratio in the nickel-titanium alloy. It also has the advantages of light weight, weak magnetic properties, high strength, fatigue resistance, high resilience and good biocompatibility. In recent years, scientists have conducted a lot of basic and applied research using this property of NiTi alloy, and developed a variety of products, which are used in the diagnosis and treatment of various clinical diseases. The NT-SMA stent can be deformed and placed into the narrow part of larynx and trachea through a small lumen; after deformation, it is tightly attached to the tracheal wall and well fixed; it is biocompatible and has no obvious damage to the tracheal mucosa, so it can be placed for a long time; the high resilience enables it to follow the bending of trachea and can be placed into all sections of trachea. A 29-year-old man with dyspnea after a car accident underwent a tracheotomy at a local hospital and could not be extubated after the operation; CT showed multiple fractures of the thyroid and cricoid cartilage and softening of the trachea, forming a stenotic ring with a stenosis of about 3 mm in diameter and 13 mm in length; we performed a supported laryngoscopy under general anesthesia and saw a circumferential stenosis under the voice box, which was slightly dilated with a dilating strip and an NT-SMA stent was placed. After a few seconds, the stent stretched out under body temperature, as if a “new tube” was laid in the collapsed tube, and a continuous flow of fresh air entered the lungs through the original laryngotracheal stenosis, and the patient’s dyspnea was immediately improved, and the tracheal tube was removed at the same time. On the second day after surgery, he was able to eat and get out of bed, and soon resumed his normal life and work.