Aims: To evaluate the effects of the Qingwen Gupi decoction (QGT) in a rat model of bleomycin-induced pulmonary fibrosis (PF), and explore the underlying mechanisms by integrating UPLC-Q-TOF/MS metabolomics and 16S rDNA sequencing of gut microbiota.Methods and Results: The animals were randomly divided into the control, PF model, pirfenidone-treated, and low-, medium-, and high-dose QGT groups. The lung tissues were examined and the expression of TGF-β, SMAD-3, and SMAD-7 mRNAs in the lung tissues were analyzed. Metabolomic profiles were analyzed by UPLC-QTOF/MS, and the intestinal flora were examined by prokaryotic 16 rDNA sequencing. Pathological examination and biochemical indices revealed that QGT treatment improved the symptoms of PF by varying degrees. Furthermore, QGT significantly downregulated TGF-β1 and Smad-3 mRNAs and increased the expression levels of Smad-7. QGT-L in particular increased the levels of 18 key metabolic biomarkers that were associated with nine gut microbial species and may exert antifibrosis effects through arachidonic acid metabolism, glycerophospholipid metabolism, and phenylalanine metabolism.Conclusions: QGT alleviated PF in a rat model through its anti-inflammatory, antioxidant, and anti-fibrotic effects, and by reversing bleomycin-induced gut dysbiosis.This study lays the foundation for further research on the pathological mechanisms of PF and the development of new drug candidates.