First aid knowledge: First, the most important should be CPR, CPR contains many elements, such as determining whether the patient’s breathing and heartbeat have stopped, usually touching the carotid artery has no pulsation, and observe whether the thorax is undulating. How to open the airway, chest compressions, artificial respiration, these are very important knowledge. Second, hemostatic dressing. Generally, it is divided into local wound pressure bandage to stop bleeding, and the proximal limb of the wound is tied and ligated to stop bleeding. Third, the external fixation of fractures, usually usually with on-site splints or hard long objects to fix the fractured limb. Fourth, spinal transport is usually applied to fractures of the cervical, thoracic, and lumbar spine, which should be carried with great care and attention, as incorrect transport is likely to lead to secondary injury of the spinal fracture, causing spinal nerve damage and resulting in serious sequelae.