There are several points to note for amputation surgery: First, the amputation incision must be fish-mouth shaped to facilitate the oval shape of the distal end of the limb after suturing to avoid skin damage due to irregularity of the distal end of the limb in the future. Secondly, after the bone is amputated, the proximal end of the bone must be filed flat to prevent the fracture end from easily piercing the soft tissue later and causing pain. Third, the length of the muscle tissue at the end of the limb is just enough to wrap around the bone. Fourth, before cutting the blood vessel, the proximal end of the vessel must be ligated, and two separate lines must be used to prevent hemorrhage due to accidental dislodgement of one line.