1.Pathogenesis Complications of surgery, trauma and congenital developmental abnormalities are the main causes. Children are at an important stage of laryngeal organ development. Trauma to the larynx causes damage to the laryngeal structures and mucous membranes, and untimely treatment often results in laryngeal stenosis due to adhesion of scar tissue in the larynx. The most important symptoms caused by laryngeal stenosis are dyspnea and dysphonia. Tracheotomy can improve dyspnea, but adolescent children are at an important stage of language formation and learning, and wearing a tracheal tube for a long time has a negative impact on children’s language development and psychology. The treatment of laryngeal stenosis in children has always been a difficult problem in the field of otolaryngology. In the past, scholars have used laryngotracheoplasty and end-toend tracheal anastomosis, but because the cartilage in the larynx of children is not yet mature, laryngotomy can easily lead to stagnation of larynx development and the formation of new scar adhesions, so the treatment effect is not satisfactory. The application of CO2 laser resection of the laryngeal scar followed by T-shaped silicone tube expansion through the tracheostomy port avoids laryngeal laceration, reduces the pain of the child, and results in a quick recovery, and achieves better treatment results. Among the causes of morbidity, there are car accidents, medical tracheal intubation, congenital laryngeal Pu, laryngeal papilloma caused by surgery, etc. Since the development of the larynx in children is not yet complete, the tracheal lumen is thin and the mucosa is fragile, too much damage to the local mucosa should be avoided during surgery, and when applying CO2 laser to remove scar tissue, the laser power should be between 2 ~ 8W to protect the normal mucosa in the larynx. The general principle is that the upper end of the T-shaped silicone tube should not exceed the level of the ventricular zone for vocal fold stenosis, otherwise it will cause choking and coughing when eating and drinking. The upper end of the T-shaped silicone tube for subglottic stenosis needs to be 5-10 mm away from the vocal cords, which are too close to the vocal cords and easily cause elastic cone edema and granulomatous hyperplasia. If the upper end of the T-shaped silicone tube is lower than the stenosis site, the tube cannot be blocked after surgery, and the tube is prone to form sputum crusts and block the lumen. The sign of successful surgery is smooth extubation and disappearance of respiratory distress. Since children are less capable of self-protection, education and protection for parents and children should be strengthened, and regular follow-up reviews should be conducted to prevent accidental dislodgement or damage to the T-shaped silicone tube.