The scalp is the surface barrier of the brain to defend against external violence. It has great elasticity and toughness, and has strong resistance to pressure and tension. Therefore, violence can be transmitted into the brain through the scalp and skull, causing damage to brain tissue, while the scalp is intact or slightly damaged. The structure of the scalp is significantly different from the skin of other parts of the body. The surface hair is dense and rich in blood supply. The subcutaneous tissue structure is dense. There are short fiber septa connecting the surface layer, subcutaneous tissue layer and galea aponeurotica layer together. The trinity is not easy to separate. It is rich in fat particles and has a certain protective effect. There is a loose connective tissue gap between the galea aponeurotica and the periosteum of the skull, which allows the scalp to slide, so it has the effect of buffering external violence. Scalp injury is the most common type of primary craniocerebral injury. It can range from slight abrasions to avulsions of the entire scalp. Its significance is that scalp injury helps to determine the location and severity of craniocerebral injury. Scalp injuries are often accompanied by varying degrees of skull and brain tissue damage, which can serve as a portal of entry for intracranial infection and cause secondary intracranial lesions. Therefore, reconstruction after scalp injury has received increasing attention.