The treatment of diabetes mellitus in pregnant women is as follows: 1, diabetes mellitus combined with pregnancy: patients need to control blood glucose, including diet control, appropriate exercise and, if necessary, insulin medication, and the standard of blood glucose control is generally less than 5.3 mmol/L for fasting blood glucose and less than 6.7 mmol/L for 2 hours after meals; 2, gestational diabetes mellitus: refers to diabetes mellitus detected by screening at 24-28 weeks of pregnancy. Patients can control blood glucose by controlling diet, taking a walk after meal and other appropriate exercises, if the effect is not good, it is recommended to use insulin for treatment. The extreme control of diet in some patients may lead to the development of the fetus being affected, which is not advisable.