The lack of uterine contraction after cesarean section causes bleeding, may be due to the following reasons: 1, in the cesarean section before labor experienced a long time, resulting in stagflation or cause intrauterine distress before doing a cesarean section, maternal fatigue, resistance to decline, which may lead to lack of uterine contraction caused by a large amount of bleeding. 2, the mother suffers from hyperemesis gravidarum can also lead to post-partum uterine contraction, which causes a large amount of bleeding. 3, the mother suffers from hyperactivity, can also lead to post-partum uterine contraction, causing The mother suffers from hyperemesis gravidarum, which can also lead to weak uterine contraction after delivery and cause massive bleeding. For bleeding caused by weak uterine contraction after cesarean section, it is recommended to give appropriate treatment as soon as possible, you can intramuscular injection of oxytocin, static oxytocin and other appropriate means to promote uterine contraction, or do uterine localized massage, can reduce bleeding, so that the uterine contraction is normal.