Postpartum haemorrhage is usually defined as blood loss of more than 500 ml within 24 hours after vaginal delivery and more than 1000 ml after caesarean section. there are many causes of postpartum haemorrhage in particular, the common ones being lack of uterine contractions, placental factors or soft birth canal laceration and coagulation disorders. One of the most common factors is weak contractions. The causes of weak contractions are subdivided into systemic factors, obstetric factors uterine factors and drug factors. Specifically, they include the following, caused by excessive maternal mental stress during labor, obvious fear of delivery, or due to too long labor time, as well as excessive physical exertion, and placenta praevia, placenta abruptio, or even hypertension during pregnancy, resulting in uterine muscle edema, which affects the contraction of the uterus. The contraction of the uterus may also be affected by fibroids or malformations of the uterus, which may lead to excessive bleeding. If the placenta is retained or implanted after delivery of the fetus, this often causes significant uterine bleeding. During normal delivery, a soft birth canal tear, such as a cervical tear, may also cause significant vaginal bleeding. Therefore, when women have postpartum hemorrhage, they should actively check the specific causes of bleeding, and also consider direct blood transfusion to replenish blood volume to avoid hemorrhagic shock and other manifestations.