The indications for amputation surgery mainly include limb ischemic gangrene, severe limb destruction, burns or electric shock injuries resulting in extensive soft tissue necrosis of the limb, frostbite, severe limb infections and so on. 1. Ischemic gangrene of the limb: ischemic gangrene of the limb caused by peripheral vascular diseases, etc; 2. severe limb destruction: such as crushing injury caused by traffic accident, etc., resulting in irreparable blood vessels and nerves or poor healing after repair, causing limb ischemic necrosis, etc; 3. burns or electric shock caused by the limb caused by a wide range of soft tissue necrosis: soft tissue necrosis may be complicated by systemic infection, renal failure, systemic multi-organ failure, etc., serious life-threatening, so need to amputate the limb to improve the condition; 4. Frostbite: severe frostbite of the limb, usually need to wait until the necrotic tissue boundaries are clear to decide whether to amputate and amputation plane; 5. Infection: such as gas gangrene or uncontrollable infection causing necrosis of the limb, which requires amputation to improve the condition; 6. malignant tumors: such as osteosarcoma, malignant melanoma, etc. involving the limb or the limb is where the primary focus is located, amputation is feasible; 7. Need to install prosthesis to improve function: even if the limb preservation is successful through various methods, but the limb has no function and skin has no sensation, but the patient needs to limb part of the limb function, such as the lower limb, can be amputated after installing prosthesis to further improve the function. The relevant patients are recommended to consult the relevant specialized doctors.