In recent years, cranial defects are very common in neurosurgery, and there are many causes of cranial defects, such as craniosynostosis, cranial trauma and craniotomy, which may leave cranial defects. Once the skull is defective, the skull will not look good, and the brain tissue will lack strong protection and may be attacked by the outside world at any time, so that it cannot function normally. Cranial defects can lead to dizziness, headache and other uncomfortable symptoms, and because of the unattractive appearance, patients will also have a sense of inferiority, and the quality of life is significantly reduced. Cranial defects really cannot be taken for granted, because the defective part is rarely possible to grow up by itself, and it needs to be repaired by surgery to restore the defective part as before, and there is no need to worry about the safety when going out. So, how to repair the skull after craniotomy? This should be combined with the patient’s own situation, to observe whether the area of the patient’s skull defect reaches the range of values specified by the surgery, if the defect area is larger than 3 cm should do skull repair surgery. Generally, if the patient has an open skull fracture with good wound cleaning, the skull repair surgery can be performed in one stage; however, if the skull defect is caused by debridement and decompression due to cranial hypertension, the skull repair should be performed 2-3 months after the surgery. It is important to choose the right time to do skull repair surgery and also to choose good materials. Titanium mesh materials are commonly used in many local hospitals, but they have many drawbacks and shortcomings, including a high chance of postoperative infection, and in a few cases, they can also cause rejection, affect postoperative examinations and cause material exposure. Unlike the PEEK material used by our team, which has excellent properties, the PEEK material effectively overcomes the problems of titanium mesh material and provides excellent postoperative contouring results. In addition, we have successfully incorporated the concept of cosmetic surgery into our surgical procedures, and we have successfully performed PEEK cranioplasty with excellent results.