PI3K inhibitor prevented pulmonary fibrosis from lung epithelial cells by reversing EMT and down‐regulation of CTGF and collagen I. Thus, our data indicate that the signalling pathway of TGF‐β1/PI3K/CTGF plays an important role in the fibrogenesis of lung epithelial cells, which may be a novel therapeutic approach for pulmonary fibrosis. Here, TGFB1 is linked to pulmonary fibrosis.