The purpose of the obstetrician to press the belly of the mother is to stimulate the uterus, so that the uterus will contract and reduce bleeding. In the postpartum period, there will be bleeding due to the abruptive surface of the placenta, and the bleeding needs to be stopped by the uterus contracting and squeezing the blood vessels to make them close. If the uterus does not contract well, the blood vessels on the abruptive surface of the placenta cannot be closed in time and more bleeding will occur. The obstetrician stimulates the uterus to contract by massaging the abdomen for the purpose of stopping the bleeding. Another purpose is to make the blood accumulated in the uterine cavity can be discharged out of the body in time. If the stagnant blood is not discharged out of the body in time, the uterus will be propped up, affecting the contraction of the uterus, and excessive bleeding will also occur.