The ability to deliver a baby by cesarean section for one child and gestational diabetes for the second child varies from person to person. When the diabetes is not severe and there are no other indications for cesarean section a trial of vaginal delivery is possible, otherwise surgical delivery is recommended. If the previous operation was a lower uterine segment cesarean section, and the current pregnancy has diabetes, but the condition is not serious, the pregnant woman does not have complications of diabetes, the estimated fetal volume is ≤3000g, and the mother has a spacious pelvis and a good cervix, a trial of labor can be performed vaginally. If the previous surgery was inverted “T” or “J” incision, longitudinal incision in the lower uterine segment, and the condition of gestational diabetes mellitus is more serious, and the mother has microvascular lesions, poor glycemic control, the fetus is too large, and placental dysfunction and abnormal fetal position are found in the late pregnancy, it is not recommended to try delivery, because the risk of normal delivery is too high, and serious complications such as uterine rupture, neonatal asphyxia, and other complications may occur. The risk of uterine rupture, neonatal asphyxia and other serious complications is too high. In general, the combination of keloid uterus and gestational diabetes mellitus makes vaginal delivery more risky. Even if a trial of labor is possible, it is important to be prepared for surgery after labor has started, and continuous electronic fetal heart rate monitoring should be given during labor, so that the patient can be referred to surgery in case of fetal distress or signs of uterine rupture.