In this study, we found that the lung oxidative stress of PF mice was significantly increased, and the test results of oxidative stress-related regulatory enzymes (SOD, MDA, and GSH) in mouse lung tissue showed that pulmonary fibrosis resulted in significant enhancement of oxidative stress and an imbalance in antioxidant capacity, but this oxidative stress was regulated after LMWF intervention. This evidence concerns the gene SOD1 and pulmonary fibrosis.