Linear facial depressed scar is caused by poor healing of skin, subcutaneous tissue or deep tissue fracture, and adhesions with facial muscles. With the contraction of muscle movement, the depressions become more obvious, affecting the aesthetics and aggravating the patient’s mind. Therefore, it is an important task for plastic and cosmetic surgeons to find the ideal treatment method. Facial depressed scars, mostly caused by trauma or infection, often have severe adhesions to deeper tissues at the base of the scar. Some patients mainly complain of depressions, and if facial expressions move and muscles contract, linear depressions become more obvious, seriously affecting facial aesthetics and spilling over into psychological state. If the treatment purpose is often not achieved by scar excision, the effect will not be satisfactory to the patient, mainly because of the re-adhesion after surgery and the appearance of local depression. To correct the deformity, different methods should be used to fill the defective area after adequate debridement of the scar base in order to restore the normal shape. The small needle knife has the advantage of being fast and less damaging. When peeling before injecting fat particles, local anesthesia combined with swelling technique can make the peeling level clear and prevent damage to deep tissues. When the linear scar is peeled, the small needle knife is used to significantly improve the peeling efficiency, maintain the peeling level, and prevent damage to the deep important nerves. When injecting fat into the peeling cavity, the amount of injection should be slightly higher than the surrounding normal skin in the affected area. Autologous fat particles injected for filling are safe and convenient to take, abundant and abundant donor source, easy to obtain, hidden incision, no rejection reaction, no ethical problems, and are more ideal human soft tissue filling materials. In addition, the autologous autologous fat tissue contains fat stem cells, which survive and proliferate in the recipient area and can prevent the surface skin tissue from adhering to the deep muscle tissue again.