Abstract: Lactic acid bacteria have a good therapeutic effect on diabetic patients, and the exploration of its mechanism has been intensified. Lactic acid bacteria can inhibit α-glucosidase in the intestine to reduce blood sugar, and reduce blood sugar levels by regulating insulin signal transduction, sugar metabolism, lipid metabolism and other related metabolic pathways. Promote insulin expression or reduce phosphorylation level to improve insulin resistance and affect the body. The glucose transport factors in turn affects glucose metabolism from the aspects of sugar reabsorption, down-regulates the expression of liposynthetase, inhibits adipogenesis, improves the abundance of intestinal flora and affects the integrity of intestinal flora, and affects inflammation and metabolic disorders to repair it. This article reviews the current research on the specific mechanism of lactic acid bacteria in improving diabetes, and provides references for the future prevention and treatment of diabetes by lactic acid bacteria.