Abstract： Objective To explore the characteristics of traditional Chinese medicine syndrome types of severe mycoplasma pneumoniae pneumonia(SMPP)in children and its relationship with changes in airway mucosa under bronchoscopy.Method From September 2023 to November 2023,106 hospitalized children with SMPP were admitted to the Traditional Chinese Medicine Department of Beijing Children's Hospital affiliated to the Capital Medical University.After admission,electronic bronchoscopy examination and traditional Chinese medicine syndrome differentiation were performed to observe the characteristics of airway mucosal changes under bronchoscopy for each syndrome type.Result(1)In the distribution of SMPP syndrome types,syndrome of phlegm dampness blocking the lung is the most common one,followed by syndrome of phlegm heat blocking the lung,syndrome of anti-pathogenic qi deficiency and retention of pathogenic factors and syndrome of lung and spleen deficiency.Children with syndrome of phlegm heat blocking the lung have the shortest course of disease,while those with lung and spleen deficiency syndrome have the longest course of disease.(2)In the syndrome of phlegm heat blocking the lung,phlegm dampness blocking the lung,and positive deficiency and evil affection,the manifestation of the bronchial lower airway is manifested as severe type,while the syndrome of lung and spleen deficiency is mainly as common type.(3)Under the microscope,rough swelling and increased secretion of the airway mucosa can be seen in all types of syndromes.The mucosal changes in the syndrome of anti-pathogenic qi deficiency and retention of pathogenic factors are mainly characterized by mucosal erosion,inflammatory stenosis,poor sub branch ventilation,and lumen occlusion.The vertical folds in the syndrome of phlegm dampness blocking the lung are the most seen among all groups.In the lung spleen qi deficiency syndrome,the main manifestations are airway mucus blockage,mucosal necrosis,epithelial attachment,and detachment.Conclusion The most common syndrome types of traditional Chinese medicine in children with SMPP is syndrome of phlegm dampness blocking the lung.In the syndrome of phlegm heat blocking the lungs,phlegm dampness blocking the lungs,and anti-pathogenic qi deficiency and retention of pathogenic factors,the manifestation of the bronchial lower airway is mainly seen in severe type.Under the microscope,obstruction of the lumen can be seen in the syndrome of phlegm dampness blocking the lungs and the syndrome of anti-pathogenic qi deficiency and retention of pathogenic factors,which increases the risk of residual BO in the later stage is visible.