Diabetic nephropathy (DN) is a clinical syndrome characterized by persistent proteinuria and progressive decline in renal function, and is one of the microvascular complications of diabetes. With the in-depth understanding of the pathogenesis of DN, the role of intestinal flora imbalance in the disease has been found clinically. This suggests that restoring the host′s healthy gut flora may be a means of improving DN. In fact, recent studies have shown that many of the drugs currently used to treat DN affect gut microbiota composition. In this review, intestinal flora is regarded as one of the main factors affecting the development of DN, and DN therapy targeting intestinal flora is summarized to provide new ideas for the diagnosis and treatment of DN.