The most serious degree of scalp injury is scalp avulsion injury. Since the blood supply to the head is very rich, a large area of scalp avulsion injury can cause a lot of bleeding in a very short period of time, and it is difficult to stop the bleeding, which can easily lead to a decrease in the patient’s blood volume and even shock. In addition, the degree of large avulsion injury is more serious and can cause localized scalp defects, which may cause scalp wound infections and even life-threatening if not well controlled later.