Abstract：Objective：To observe the effect of Yangyin Qingfei tang on lung function in patients with pneumoconiosis in stable stage and its mechanism of improving lung fibrin. Methods：A total of 70 cases of patients with pneumoconiosis were selected and divided into the routine group，the Yangyin Qingfei tang group and the pirfenidone group according to different treatment methods，with 10，30 and 30 cases in each group respectively. The routine group was treated with conventional inhalation preparations， oxygen inhalation， suppressing cough， resolving sputum and relieving asthma， and the Yangyin Qingfei tang group was additionally treated with Yangyin Qingfei tang based on the routine treatment， and the pirfenidone capsules group was additionally treated with pirfenidone capsules based on routine treatment. Before treatment and after 4 and 16 weeks of treatment，the levels of forced vital capacity(FVC)，forced expiratory volume in one second(FEV1) and FEV1/ FVC in the three groups were compared. Before and after treatment，the levels of CD3+，CD4+，CD8+ and CD4+/CD8+ in the peripheral blood，transforming growth factor β1(TGF- β1)，interleukin- 2(IL- 2)，and interleukin- 17(IL- 17) were detected. The quality of life in the two groups was evaluated by Modified Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ- M)， and the incidences of adverse reactions were observed. Results： After 4 and 16 weeks of treatment， the levels of FEV1，FVC and FEV1/FVC in the three groups were gradually increased，and the levels of FEV1，FVC and FEV1/FVC in the Yangyin Qingfei tang group and the pirfenidone group were higher than those in the routine group at the same time period，differences being significant(P＜0.05). After treatment，the levels of CD3+，CD4+ and CD4+/CD8+ in the three groups were increased when compared with those before treatment， and CD8 + levels were decreased， the difference being significant(P＜0.05). After treatment，the levels of CD3 +，CD4 + and CD4 +/CD8 + in the Yangyin Qingfei tang group and the pirfenidone group were higher than those in the routine group，and the CD8+ levels were lower(P＜0.05)；the levels of CD3+， CD4+ and CD4+/CD8+ in the Yangyin Qingfei tang group were higher than those in the pirfenidone group，and the CD8+ level was lower(P＜0.05). After treatment， the levels of TGF- β1， IL- 2 and IL- 17 in the three groups were decreased when compared with those before treatment，and the levels of TGF-β1，IL-2 and IL-17 in the Yangyin Qingfei tang group and the pirfenidone group were lower than those in the routine group，and the TGF-β1，IL-2 and IL-17 in the Yangyin Qingfei tang group were lower than those in the pirfenidone group，differences being significant(P＜0.05). After treatment，the PFSDQM scores in the three groups were decreased when compared with those before treatment，and the PFSDQ-M scores in the Yangyin Qingfei tang group and the pirfenidone group were lower than that in the routine group，and the PFSDQ-M score in the Yangyin Qingfei tang group was lower than that in the pirfenidone group， differences being significant(P＜0.05). The incidences of adverse reactions in the Yangyin Qingfei tang group and the pirfenidone group were lower than those in the routine group，and the incidence of adverse reaction in the Yangyin Qingfei tang group was lower than that in the pirfenidone group(P＜0.05). Conclusion： Yangyin Qingfei tang can significantly improve lung function and lung fibrin in patients with pneumoconiosis，with good prognosis and high safety.