Insulin sensitizers act to increase insulin sensitivity. The mechanism of diabetes mellitus is insufficient insulin secretion and insulin resistance, and uncontrolled blood sugar. Insulin resistance means that insulin sensitivity is reduced and insulin cannot play a corresponding role in lowering glucose, and insulin sensitizers can promote insulin to lower glucose. However, the current role of insulin sensitizers is subject to certain restrictions, such as insulin sensitizers thiazolidinediones have side effects, which can increase the risk of edema and heart failure, and their indications should be strictly controlled. In addition, metformin, which has insulin-sensitizing effect, can be the drug of choice for lowering glucose. It has insulin-sensitizing effect, which can inhibit hepatic glucose output and promote the utilization of glucose by peripheral tissues. Other drugs also have insulin-sensitizing effects, such as glimepiride, which acts after the insulin receptor and can increase insulin sensitivity.