Failure of operation will lead to facial droop 1, and the old or wrong design of operation scheme will lead to the position of zygomatic bone and zygomatic arch after operation. 2. No fixation was done during the operation, and the position of cheekbone moved down after the operation; It was fixed during the operation, but the bone did not heal well and the cheekbone moved down. 3. The soft tissue injury is too large, which leads to the whole downward movement of the healed soft tissue. The function of facial expression muscles is impaired, especially the change of smile. When smiling, the lifting of the corners of the mouth is restricted and drooping appears. Unreasonable surgical design, improper handling during operation or self-recovery after operation may all lead to postoperative facial ptosis. Successful zygomatic arch plastic surgery can perfectly avoid the problem of facial drooping after operation.