The common causes of umbilical bleeding in newborns are, 1. umbilical infection. 2. abnormal coagulation function. The first cause is umbilical bleeding due to secondary infection before and after the umbilical cord is shed. If this is the cause, we need to strengthen umbilical care by disinfecting the deep part of the umbilical fossa with medical cotton swabs dipped in Amyl iodine two to three times a day, and applying topical Bactrim ointment to reduce inflammation. The second cause of umbilical bleeding is the abnormal coagulation function caused by vitamin K1 deficiency, which is common in exclusively breastfed children, manifesting as umbilical bleeding, gastrointestinal bleeding, and in severe cases, intracranial bleeding, so if this is the case, timely medical examination and treatment is necessary.