Thinning thick lips is not a very complicated operation in lip plastic surgery. However, due to intraoperative trauma, improper operation by doctors and other reasons, some surgical risks will inevitably occur, among which the biggest risk is that the operation fails and the expected effect cannot be achieved. In view of this situation, only by finding out the location and cause of the fault can it be completely repaired through re-operation. There are many reasons why lips become thicker and thinner. Whether it is congenital lip hypertrophy or acquired lip hypertrophy, such thick lips can make the lips of beauty seekers look better by thinning. The operation of thinning the thick lip is to cut off an oral mucosa and muscle in a spindle or zigzag way according to the thickness of the upper and lower lips, and then directly cut the suture incision to achieve the effect of thinning the thick lip. Then, 1, Lip asymmetry: after the thick lip thinning operation is completed, if bilateral lip asymmetry is found, it means that the operation failed. This is mainly because the length, width and amount of red tissue on both sides of the lips are inconsistent when doctors perform red lip resection, which may lead to asymmetry on both sides of the lips. The amount of red lip tissue resection is inconsistent, which leads to the asymmetry of the lip after the operation. In this case, the patient needs a second operation to repair. 2. Unnatural squabble: After the thick lip thinning operation is completed, the unnatural squabble on both sides of the patient's lips is also a sign of surgical failure. Generally, this happens because the doctor opens the surgical incision too close to the mouth corner during the operation, or when the redundant red lip is removed at the mouth corner, the amount of removal is insufficient or excessive. In this case, local plastic surgery such as Z plastic surgery can be performed after 36 months. Because too much lip bead tissue was removed. The width of the resected tissue can be appropriately narrowed at lip bead to make it V-shaped, and the orbicularis oris muscle at lip bead can be left untouched or less resected.