Abstract: In this paper, a 3D model of real human laryngotracheal airways was reconstructed based on computed tomography (CT) image data, and airway models with different subglottic laryngotracheal stenosis were then constructed. Computational fluid dynamics simulations under inspiratory conditions were performed on these airway models. The flow field characteristics of the laryngotracheal airway in different stenosis classification models, the resistance characteristics of different laryngotracheal segments, and the pressure and shear stress distribution of the flow field on the laryngotracheal wall were analyzed and compared. The correlation between these characteristics and clinical phenomena is discussed. The analysis showed that graduation is well correlated with the respiratory tract resistance caused by subglottic laryngeal tracheal stenosis; in addition, the negative airflow pressure and shear stress effect caused by laryngotracheal stenosis should be paid sufficient attention to the effect on the course of the disease in clinical treatment.