The types of craniocerebral injuries caused by car accidents are divided into primary craniocerebral injuries and secondary craniocerebral injuries according to the time of the onset of the disease; light craniocerebral injuries, medium craniocerebral injuries and heavy craniocerebral injuries according to the degree of damage to the brain tissues; and open craniocerebral injuries and closed craniocerebral injuries according to whether or not the brain tissues after the injuries are connected to the outside world. Craniocerebral injury caused by car accident belongs to traumatic craniocerebral injury. The classification method is the same as traumatic brain injury. 1. According to the time of onset (1). Primary craniocerebral injury: it means that the brain tissue of the head is damaged immediately after the trauma and the corresponding clinical symptoms appear. (2). Secondary craniocerebral injury: after a period of time, the brain tissue of the head is damaged after trauma, a series of clinical symptoms caused by cerebral hemorrhage and cerebral edema will appear. 2. Degree of brain tissue injury (1). Mild craniocerebral injury: the time for the patient to become unconscious after trauma is within 30 minutes. (2). Medium-type craniocerebral injury: the time for the patient to be in coma after the trauma is within 12 hours. (3). Severe craniocerebral injury: the time for the patient to be in coma after the trauma is more than 12 hours. 3. Whether the brain tissue is connected to the outside world after the injury. (1). Open Craniocerebral Injury: after the car accident, the patient’s head trauma causes the brain tissue to be connected with the outside world, and is accompanied by obvious bleeding from the scalp wound, cracking of the skull, and impaired consciousness. (2). Closed craniocerebral injury: the brain tissue of the patient’s head after the car accident is not connected with the outside world, and often has cerebral contusion, concussion, intracranial hematoma, etc. Craniocerebral injuries found after car accidents need to go to the hospital in time for examination and treatment, so as not to delay the condition.