The first aid splint provides fixed support for patients with fractures and injuries in different body parts. It is easy to operate, fast to use, strong protective, and can be used for X-ray imaging and magnetic resonance examination. It can avoid aggravating the injury due to the movement of the fracture site during the transfer of the injured person, and can effectively prevent secondary damage caused by improper on-site handling and hospitalization, pain, bleeding, etc. caused by stabbing muscles, nerves, blood vessels or organs at the fracture end