To explore the mechanism of the combination therapy with DHA and BMSCs in inhibiting renal fibrosis, mouse podocyte fibrosis was induced in vitro, and SB431542 intervention was administered to prove that the combination therapy with DHA and BMSCs inhibited renal fibrosis through the inhibitory TGF-β1/Smad pathway. This evidence concerns the gene TGFB1 and renal fibrosis.