Abstract: Diabetes is a chronic metabolic disease caused by multiple factors, and it is an epidemic worldwide in the 21st century. The intestinal flora of diabetic patients is imbalanced, with reduced antioxidant capacity and low-grade inflammation. Relevant studies have shown that probiotics, as a kind of living microorganisms that are beneficial to the health of the intestine, can relieve the symptoms of diabetes by balancing the intestinal flora, reducing the body's oxidative damage and regulating the body's immune factors. This article combs the two commonly used methods for screening hypoglycemic strains with α-glucosidase and DPP-IV as targets, and evaluates the hypoglycemic effect of probiotics through in vivo experiments. At the same time, it further summarizes the mechanism of probiotics in alleviating type 2 diabetes from five aspects such as intestinal flora, immune response, oxidative stress, short-chain fatty acids and intestinal barrier, in order to provide a certain reference for related research on type 2 diabetes.