In this study, the influence of miRNA-30a-5p on the pulmonary fibrosis in mice through the regulation of autophagy by Beclin-1 was observed, and according to the gene detection results, the inhibitors group had substantially raised gene expression levels of LC3 and Beclin-1, but notably lowered gene expression levels of p62 and α-SMA, while the mimics group exhibited the opposite conditions. The gene discussed is MAP1LC3A; the disease is pulmonary fibrosis.