First of all, the doctor should determine the starting point and stopping point of epicanthus in the state of natural eye opening, draw marks with gentian violet, perform local infiltration anesthesia with 2% lidocaine, let the patient close his eyes, cut the skin and orbicularis oculi muscle along the preoperative design line, fully free the flap, let the patient open his eyes and see the correction effect of epicanthus. After exchanging the position of the double triangular valve, the operation is completed.