Gestational diabetes mellitus can be diagnosed during pregnancy when the glucose tolerance test indicates that the blood glucose two hours after sugar consumption is 9.4mmol/L. Most of them only need to be controlled by diet and exercise, and are generally not serious. Generally in pregnancy 24 ~ 28 weeks routine recommended 75 grams of glucose tolerance test screening for gestational diabetes, normal fasting blood glucose, one hour after taking sugar, two hours after taking sugar blood glucose normal value of 5.1, 10.0, 8.5 mmol / L or less, when one of the blood glucose value is out of the normal range can be diagnosed as gestational diabetes mellitus. Most pregnant women can control their blood glucose through dietary adjustments and moderate activities, which is generally not serious, and insulin treatment should be given when blood glucose control is still unsatisfactory after diet and exercise control. Gestational diabetes mellitus is a common disease during pregnancy, poor glycemic control can increase the risk of fetal growth restriction, macrosomia, hypertensive disorders of pregnancy, infectious diseases during pregnancy and puerperium, when pregnancy checkups indicate elevated blood glucose, pregnant women and their families should pay great attention to it and monitor blood glucose under the guidance of obstetricians.