The anterolateral femoral flap, which is commonly referred to as the anterolateral thigh flap, is one of the many flaps used to repair tissue defects in various parts of our body. Since its discovery by our scholars in 1982, this flap has been rapidly accepted and applied by scholars all over the world, starting with extremity defects and then gradually applied to the repair of head and neck defects, and now it has become the first-line flap for the repair of soft tissue defects of the head and neck. So why do we talk about flap repair, which defects need flap repair, what is the effect of repair, and are there any sequelae? I think this is the first question that most patients think of when they hear about flap repair. First of all, the primary purpose of surgical treatment of head and neck tumor is to completely remove the tumor to achieve the effect of radical cure, therefore, sufficient safety boundary should be removed in all directions during the process of tumor removal. In the past, due to the lack of ideal repair means, the surgeon should first ensure that the wound can be closed, which may lead to insufficient tumor resection boundary and tumor recurrence. Therefore, the surgeon should only perform lesion excision as needed for radical treatment if it is clear that the surgical defect can be properly repaired. The severe facial deformity of patients after resection, the inability of some patients to go out and see others at all, and the risk of tumor recurrence, all of these are painful for the patients to imagine. The free tissue flap grafting technique developed in the past 30 years has provided head and neck surgeons with the assurance of adequate and appropriate removal of tumors and repair of defects, which greatly reduces the recurrence rate of tumors after surgery and improves the survival rate of patients; and because the defects can be repaired in time, the quality of life of patients after surgery is greatly improved. Defect sites in the head and neck can be broadly classified as oral cavity (e.g. tongue, lips, cheek, floor of mouth), jaws, face, skull base, skin and scalp. In the past, different free tissue flaps had been selected according to the principle of similar tissue replacement, different sites and tissue defects. However, different flaps have their own limitations of application and risk of failure depending on the difficulty of flap preparation, tissue volume and postoperative donor area complications. Thus, the anterolateral femoral flap came to the forefront. The anterolateral femoral flap is suitable for a variety of soft tissue defects of different sizes and locations in the head and neck. The maximum length of the flap can be taken up to 35 cm, and the thickness ranges from ultrathin flap to fascial flap to myocutaneous flap, in the form of one tip with two islands, one tip with multiple islands, and the flap from the other leg can be taken if one side is not enough. This allows for the repair of almost all soft tissue defects of the head and neck. The advantages of the anterolateral femoral flap include: 1. the donor area is concealed, as the skin is taken from the anterolateral thigh and is undetectable as long as shorts and skirts are not worn; 2. the amount of tissue is large, as mentioned above; 3. the major vessels are not sacrificed, as the anterolateral femoral flap utilizes the blood supply from the penetrating vessels without damaging the major vessels of the leg; 4. most of the flaps do not require skin grafting and can be directly pulled together and sutured; and 5. the two-group procedure. Two groups operate simultaneously, which saves surgical time and ensures surgical safety; 6. The donor area has few complications, and postoperative leg function and sensation are basically unaffected. The anterolateral femoral flap can repair not only postoperative head and neck tumor defects but also congenital and acquired deformities of the head and neck. Therefore, the anterolateral femoral flap is not only a commonly used flap by head and neck oncologic surgeons, but also favored by plastic and cosmetic surgeons. The anterolateral femoral flap has become an ideal flap for the repair of soft tissue defects in the head and neck. Our group, led by Professor Keqian Zhi, director of head and neck tumor surgery, was the first to carry out anterolateral femoral free flap repair of postoperative head and neck tumor defects in our hospital, and received excellent treatment results and good comments from patients.