Jaw plastic surgery is very strict and precise, which requires a series of predictive analysis and simulation operations to determine the operation mode, osteotomy location, direction and distance of bone segment movement, occlusion relationship, etc., in order to ensure the success of the operation. Before the operation, a lateral X-ray of skull should be taken. On this X-ray, the relationship between skull, jaw, teeth and jaw and the structure of facial soft tissue should be measured, and the outline of skull, jaw, teeth and facial soft tissue should be outlined with cellophane. Through paper-cutting and spelling, we can predict the position, distance and direction of the cheekbones that need to be moved during the operation and predict the changes after the operation.