There are many risk factors for the formation of postpartum hematoma after vaginal delivery.Larger vulvovaginal hematomas or special types of hematomas，such as broad ligament hematoma and/or retroperitoneal hematoma，often have occult onset and are difficult to detect early，which can cause occult postpartum hemorrhage and endanger the life of pregnant women.According to the location and size of hematoma，whether it continues to increase，and the stability of maternal hemodynamics，conservative treatment，pelvic artery embolization or surgical treatment can be selected.