Hypoglycemia is a common problem in the pregnant women with gestational diabetes. Hypoglycemia is a potential and severe complication, which threatens the health of mothers and fetus. Hypoglycemia not only leads to syncope, consciousness disorders, seizure and even maternal death, but also affects the maternal system and fetal development. In clinical practice, strict measures should be taken to monitor blood sugar, more attention should be paid to notice the severe hypoglycemia and make early diagnosis, and establish personalized insulin regimen, which are in order to prevent severe hypoglycemia in pregnancy.