To observe the effect of Suzi Jiangqi Decoction on pulmonary function and quality of life of acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and to explore its mechanism.Methods:A total of 108 cases of patients with AECOPD with turbid phlegm obstructing lung syndrome in our hospital from January 2015 to May 2017 were selected and randomly divided into control group and observation group according to random number table method, with 54 cases in each group; The observation group：on the basis of Western medicine treatment in the control group, given oral administration of Suzi Jiangqi Decoction based on syndrome differentiation.According to the lung function and life quality of TCM syndrome score changes, the effect of Suzi Jiangqi Decoction on phlegm obstructing lung type AECOPD was observed, and enzyme linked immunosorbent assay (ELISA) method was used to detect IL-21 and CXCL13 levels.Results:Compared with those before treatment, the TCM syndrome scores of two groups were significantly lower than those before treatment (P<0.05), and the observation group was significantly lower than that in the control group after treatment (P<0.05).After treatment, the lung function of the two groups increased compared with that before treatment.However, the main indicators of lung function in the observation group FVC (L), FEV1 (L), FEV1/FVC (%) and PEF (L/s) were significantly better than those in the control group (P<0.05).After treatment, the symptom, activity, influence and average score of quality of life in the observation group were significantly lower than that of the control group (P<0.05).After treatment, the expression level of IL-21 and CXCL13 in the 2 groups was significantly decreased (P<0.05), and the observation group was better than the control group (P<0.05).Conclusion:Suzi Jiangqi Decoction can obviously improve the phlegm obstructing lung type AECOPD disease, improve lung function and life quality of the patients, and the mechanism may be related to the decrease of peripheral blood IL-21 and CXCL13 concentration.