Oral hypoglycemic drugs mainly include the traditional five major classes, including sulfonylureas, glinides, biguanides, α-glucosidase inhibitors, and thiazolidinediones. At present, new oral hypoglycemic drugs have been developed and marketed, such as DPP-4 inhibitors, SGLT-2 inhibitors. I. Traditional drugs 1. Sulfonylurea: Sulfonylurea is a pro-secretory agent of insulin, which mainly promotes the secretion of insulin by pancreatic beta cells to help the body lower blood sugar. Sulfonylurea hypoglycemic drugs are more effective than other types of hypoglycemic drugs, commonly used drugs such as glipizide, gliclazide, glibenclamide, glimepiride, gliquidone, etc.; 2. Glinides: such as Repaglinide, Naglinide, Miglinide, etc., are also insulin secretagogues, but the mechanism of action is not the same as sulfonylureas, and the duration of action is relatively short, so the risk of hypoglycemia is relatively small. 3.Biguanide: more common is metformin, which is a sensitizer of insulin and can improve the sensitivity of peripheral tissues to insulin, and is usually the first-line drug of choice for overweight and obese patients with type 2 diabetes; 4.α-glucosidase inhibitors: commonly used are acarbose, voglibose, miglitol, etc. These drugs can mainly inhibit the absorption of monosaccharide in the intestine and help control postprandial blood sugar. For patients who like to eat carbohydrates, the effect of reducing postprandial blood sugar is better; 5. Thiazolidinediones: such as rosiglitazone, pioglitazone, etc., belong to the insulin sensitizer, usually for insulin-resistant diabetic patients with better results, when applied, attention should be paid to the impact on liver function and bone metabolism. Second, newly developed drugs 1, DPP-4 inhibitors: that is, dipeptidyl peptidase 4 inhibitors, such as sitagliptin, saxagliptin, ligliptin, etc., can improve and regulate the ability of pancreatic alpha cells, secretion of glucagon. It can also delay gastric emptying, so it has good efficacy for postprandial blood glucose level. 2. SGLT-2 inhibitors: i.e. sodium-glucose co-transporter protein 2, such as daglitazone, enaglitazone and kaglitazone, etc. These drugs mainly promote glucose excretion from the kidney. Its mechanism of action is not the same as that of the previous traditional drugs, and it is a large new class of hypoglycemic drugs.