After a large area of skin and soft tissue injury defect of the extremities, the bones and tendons are exposed, and the trauma is seriously infected and necrotic. If improperly treated, it will inevitably lead to complications such as osteonecrosis and osteomyelitis. At present, free (muscle) flaps have become an effective method to repair skin and soft tissue defects in the foot and ankle. Most of the patients admitted to our department with traumatic exposures were transferred from foreign aid, and were admitted with long treatment time in foreign hospitals and serious traumatic exudation and infection, so after admission, traumatic debridement was performed first, and those with combined fractures were fixed with fracture repositioning, clincher pins or external fixation frame at the same time. The trauma was covered with continuous negative pressure drainage, and the trauma was repaired with a myocutaneous flap after the necrosis was clearly defined. After surgery, the flap was well established and the donor area was healed in one stage. All patients were followed up for 2 months to 2 years, and all flaps were soft and colorful without local ulceration. Fractures of the extremities combined with large soft tissue defects are common in clinical practice, and the bones and tendons are exposed after the injury. The area of free anterolateral femoral flap can be cut as needed, which can effectively close the wound and has strong resistance to infection, and is a safe and reliable ideal method for repairing large skin and soft tissue defects in the foot and ankle. The application of free anterolateral femoral flap graft to repair large skin and soft tissue defects in the foot and ankle has the following advantages: (1) The anatomy of the descending branch of the lateral femoral artery of the anterolateral femoral flap is more constant and less variable, and it can be marked with color ultrasound Doppler flow detector before surgery. Moreover, it can be anastomosed with a long vessel tip, and the caliber of the vessel is similar to that of the anterior and posterior tibial arteries and their accompanying veins, so it is easy to be anastomosed without tension. (2) The flap contains the lateral femoral cutaneous nerve, which can be anastomosed with several nerves in the trauma, such as superficial peroneal nerve, saphenous nerve and peroneal nerve, to restore sensation to the trauma. (3) The skin of the thigh is very elastic, and after excision of the musculocutaneous flap, the wound can be directly sutured in most of the patients, and in a few patients, skin implants are taken. There are no important blood vessels and nerve bundles in the anterolateral thigh, and the location is concealed, so there is no significant impact on the shape and function of the donor area after excision.