There are several principles of first aid at the scene: 1. The patient’s vital signs must be closely observed and stabilized, and if the patient’s breathing and heartbeat have stopped, cardiopulmonary resuscitation should be given at the scene, and if possible, intravenous access can be established at the scene to give epinephrine and other rescue drugs. 2. 3, for the wound, fracture dressing, wound bleeding first give pressure dressing. If the bleeding does not stop, it may be a relatively large vascular injury and a tourniquet or bandage must be given at the proximal end of the limb to block the blood flow; for fractures, such as limb fractures, a splint or brace can be given for external fixation; for spinal fractures, the cervical spine can be externally fixed with a cervical girth; the lumbar spine can be externally fixed with a lumbar girth.4. Fast and effective transfer to the hospital for further examination and treatment. If a spinal fracture is suspected during the transfer process, the patient must be transported lying down with a spinal board or with a hard wooden board to avoid secondary injury caused by displacement of the spinal fracture.