Abstract： Mycoplasma pneumoniae pneumonia is a common infectious lung disease in children,and severe cases of mycoplasma pneumoniae pneumonia can endanger the lives of children.Professor YAN Hui-min believes that the abnormal rise and fall of qi is the fundamental pathogenesis of severe mycoplasma pneumoniae pneumonia.Understanding the changes in qi movement and giving treatment as soon as possible can prevent the occurrence of severe mycoplasma pneumoniae pneumonia and provide effective treatment.Professor YAN made syndrome differentiation and treatment from multiple perspectives,such as failure of lung qi to disperse and descend,unfavorable gasification of Three Jiao,phlegm heat blocking and suppressing qi movement,and dysfunction of spleen and stomach in ascending and descending,to ensure orderly ascending and descending of qi.The lung loses its ability to promote diuresis,and the self-designed Maxing Xuanjiang Tang can promote dispersing and descending of lung qi.If the gasification is unfavorable and the water dampness stagnates,choose Sanren Tang to activate lung qi in the Upper Jiao.Due to the accumulation of pathogenic heat and obstruction of phlegm in the airways,the treatment is to clear heat,disperse lung qi,and promote bowel movement,then Qianjin Weijing Tang and Dachengqi Tang are used to treat this condition.If the spleen and stomach are abnormal in ascending and descending,the prescription is modified Banxia Xiexin Tang to regulate the spleen and stomach and increase the clear and reduce turbidity.