Cranial injuries often occur in patients and are commonly caused by traffic accidents, falls from height, falls, industrial accidents, and firearm injuries. For patients with severe craniocerebral injury, sometimes craniotomy may be required, and in the case of intracranial hypertension, debridement and decompression may be required, leaving a skull defect after surgery. Some patients ask about the cranial defects left after decompression of the flap in heavy cranial injury like this. What are the preoperative instructions for cranial defect repair? First of all, we should avoid strenuous exercise, pay attention to protection and avoid bumping; in addition, we should pay attention to keep the defect area dry and clean; we should pay attention to diet, both to ensure sufficient nutrition and to avoid too much greasy meat and fishy, and keep a light and healthy diet; we should pay attention to rest in life, ensure sufficient sleep and avoid strain; in addition, we should keep a happy mood. The last and the most important point is still to carry out skull repair in time, generally about three months in trauma surgery is the best time to repair. To do skull repair surgery, patients need to pay attention to two points, one is to choose the right repair material, but choose a good hospital doctor. Although cranial bone repair is a routine surgery, it is not simple. The repair material is important, as are the surgical skills and perioperative care of the health care team. Currently, polyether ether ketone PEEK is an ideal material with excellent properties comparable to those of autologous cranial bone, and has become a new trend in cranial repair materials because of its protective, comfortable, and aesthetic properties after placement in the body. Our team is widely using PEEK as a cranial repair material, and we are constantly improving the technology and optimizing the design of the material, as well as innovatively introducing the concept of aesthetic plastic surgery, so as to carry out comprehensive PEEK cranial repair and plastic surgery, which can achieve anatomical integrity, functional perfection, and aesthetic appearance of the overall unity, and achieve good repair results, which are widely praised.