Tracheal obstruction is a narrowing of the airway caused by various benign or malignant etiologies, which manifests as inspiratory dyspnea and the appearance of the typical trigone sign, i.e., a significant depression in the supraclavicular fossa, suprasternal fossa and intercostal space caused by forceful inspiration, and is a sign of very serious tracheal obstruction. With the development of respiratory endoscopic interventions, tracheal obstruction has been paid more and more attention. Once tracheal obstruction occurs, it should be seen immediately at a specialized hospital and endoscopic intervention should be performed quickly to relieve the obstruction and achieve good results.