Whether the preparation before mandibular angle plastic surgery is sufficient will not only affect the smooth operation process, but also affect the postoperative recovery to a certain extent, so preoperative examination is not only necessary, but also must be paid attention to. Before mandibular angle plastic surgery, beauty seekers need to reach: 1. Good health, no important organic diseases, such as heart disease, hepatitis, nephritis, pneumonia and other diseases. 2. No source of oral infection, such as tooth decay, periodontitis, oral ulcer, etc. 3. Women should avoid menstrual period during surgery. Aspirin, birth control pills and some anti-inflammatory drugs can cause increased bleeding, so these drugs should be stopped for a period of time before surgery. Because mandibular angle plastic surgery is a traumatic operation, the following strict examination should be done before operation: 1. Clinical examination: excluding cardiovascular, lung, liver, kidney and other organic diseases. 2. Laboratory examination: including blood routine, bleeding and clotting time, blood type, liver and kidney function, electrocardiogram, chest X-ray, etc. 3. Imaging examination: mainly X-ray examination, taking X-ray film of maxilla to understand the development degree of maxillary sinus. 4. Routine frontal and lateral photos of the face were taken to compare the postoperative curative effect. Three-dimensional skull CT can be done if possible, and facial models should be taken in individual cases to accurately measure the bone mass that needs to be removed from cheekbones.