Burns to amputate the limb may be due to electric shock injury, large area deep burns or serious infection after burns, and so on. 1. Electrocution: high-voltage electric current flows rapidly into the body, it keeps flowing through the limbs, but also along the large blood vessels in the body, periosteum, subcutaneous tissues of the arteries and veins of the blood flow, affecting the blood circulation, resulting in necrosis of the body tissues, and therefore need to amputate the limb. 2. Large and deep burns: when the burn area is large and deep, the muscles, blood vessels and nerves of the tissues are severely damaged and cannot survive, so amputation is needed. 3. Serious infection: serious infection of the burned limb should be treated by amputation, otherwise it will easily cause sepsis, resulting in systemic infection and threatening the life. After burns should be as soon as possible to seek medical treatment, burn depth judgment, and be treated accordingly, so as not to delay the condition.