In case of hand trauma. First, take measures to stop the bleeding. Pressure on the proximal end of the wound to stop bleeding and local compression dressing to stop bleeding are easy and effective methods. Use sterile dressings or clean handkerchiefs, towels or clothing to bandage the wound. If the major artery of the hand is injured with hemorrhage, a tourniquet or elastic hose can be used to restrain the upper arm 1/3 part to stop bleeding. However, the tourniquet should be loosened every hour for 5-10 minutes when sent to a major hospital for surgery to avoid ischemic necrosis of the hand. Next, disinfection should be performed to prevent infection. Red mercury, alcohol and iodine can be used for skin disinfection, but alcohol and iodine should be avoided to directly stimulate the lining of the cured trabecular vessels and affect the success of reattachment. If it is a severed limb, it should be packed in a clean plastic bag and placed in ice, never put the severed limb directly in the ice to avoid frostbite and infection. General cooling to 4 degrees Celsius is appropriate, so that the tissue can extend the survival of 2-4 hours. At room temperature, the amputated limb should be operated within 6 hours, and when it is cold, it should also be surgically reimplanted within 8 hours, so that the surgical result is better.