Currently, the possibility exists that type 2 diabetes insulin function can be restored and cured, but there are many prerequisites for restoration of insulin function and subsequent blood glucose monitoring is still required. The approach consists of five areas: prevention, weight loss, intensive glucose reduction, metabolic surgery, and pancreas or islet transplantation. The mechanism is primarily to restore the individual’s fat threshold, release glucolipid toxicity, or improve gut hormones and gut flora so that de-differentiated insulin beta-cells regain the ability to secrete insulin. Pre-diabetes is the best time to reverse diabetes, in pre-diabetes need to carry out lifestyle intervention, through diet and exercise therapy and other interventions to achieve the effect of weight loss, so as to improve the body’s insulin sensitivity, which promotes the transformation of pre-diabetes to normal glucose metabolism; if the effect of lifestyle improvement is not good, it can be added to the use of medication, such as pioglitazone and so on. The treatment of type 1 diabetes mellitus is mainly insulin, and type 2 diabetes mellitus is mainly oral medication, which can be combined with insulin therapy if necessary. Oral drugs include biguanides, α-glucosidase inhibitors, sulfonylureas, glinides, dipeptidyl peptidase 4 inhibitors, thiazolidinediones, sodium-glucose co-transporter protein 2 inhibitors, etc., all of which are glucose-lowering drugs that can control blood glucose. Each type of hypoglycemic agent has a different hypoglycemic mechanism, and it is necessary to follow the doctor’s instructions to choose the appropriate hypoglycemic agent according to the patient’s condition.