Abstract: Diabetes is one of the most prevalent and critical public health problems in the world, with a sharp rise in its incidence, and a significant increase in its complications as cardiovascular, ocular, renal and neurological diseases, resulting in risks for being cripple or fatal.Symbiotic bacteria are of great significance to human health, and more and more studies show that intestinal flora is closely related to the occurrence and development of diabetes.The relationship between host gene, immune system, diet and intestinal flora has been constantly revealed, and the regulation of intestinal flora is an effective measure for diabetes treatment.This article reviews the changes of intestinal flora in type 2 diabetes mellitus, the mechanism of inducing type 2 diabetes and the latest development of the effect of intestinal flora regulation on type 2 diabetes.