Mandibular liposuction is performed under local anesthesia. Make a 2-3mm skin incision in the middle of the chin, then inject swelling liquid (including painkillers and hemostatic drugs) into the subcutaneous fat layer, and then suck out the fat. Mandibular liposuction can suck out subcutaneous fat from chin to the upper neck above thyroid cartilage and below the mandibular margin on both sides, and restore the space from chin to neck. After liposuction of mandible, incision drainage should be done, local pressure should be applied to change the dressing, and the dressing should be changed two days after operation. After 3-4 days, it was replaced by elastic belt of mandibular neck for local compression and shaping. The suture was removed 6-7 days after operation, and the local compression plasticity was 1-2 months, and the effect was good.