【Abstract】 Objective To explore the effect of Yifei Sanjie Recipe on the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/rapamycin target molecule (mTOR) signaling pathway Influence. Methods 50 SD rats were randomly divided into model group (PF group), low (7.5 g/kg), medium (15 g/kg) and high (30 g/kg) groups with 10 rats in each group. The control group and PF group were given normal saline by gavage, while the Yifei Sanjie Decoction groups were given the corresponding dose of drugs once a day for 21 days. 12 hours after the last administration, the rats were killed and the lung tissue was taken. The pathological morphology of lung tissue was observed by hematoxylin eosin staining (he). Masson staining was used to evaluate the degree of collagen proliferation. The content of collagen was determined by hydroxyproline kit. Western blot was used to detect the expression of p-PI3K/PI3K, p-Akt/Akt, p-mTOR/mTOR, autophagy related protein Beclin 1, ubiquitin and LC3 binding protein p62 (p62), α smooth actin (α-SMA), microtubule associated protein light chain 3 (LC3-Ⅱ)/LC3-Ⅰ. Results Compared with the control group, the scores of inflammatory cell infiltration and inflammatory degree, the degree and score of collagen proliferation, the content of collagen, the relative expression levels of pathway proteins p-PI3K/PI3K, p-Akt/Akt, p-mTOR/mTOR, the autophagy related proteins (α-SMA and p62) were increased in PF group (all P＜0.05), and the autophagy related proteins Beclin 1 and LC3Ⅱ were increased in PF group/ LC3Ⅰ decreased (P＜0.05). Compared with PF group, the inflammatory cell infiltration and inflammatory degree score, collagen proliferation degree and score, collagen content, relative expression levels of pathway proteins p-PI-3K/PI-3K, p-Akt/Akt, p-mTOR/mTOR, autophagy related protein (a) SMA and p62 were significantly decreased (P＜0.05), and autophagy related proteins Beclin 1 and LC3-Ⅱ were decreased in Yifei Sanjie Decoction group/LC3-Ⅰ increased (P＜0.05). Conclusion Yifei Sanjie decoction can inhibit the expression of PI3K/Akt/mTOR signaling pathway, improve the autophagy activity of lung tissue cells, and alleviate the pulmonary fibrosis process.