The skull is a very important bone in the human body, which plays an important role in protecting brain tissue, maintaining normal intracranial pressure, and maintaining a stable intracranial environment. However, there are some unpredictable risk factors that may lead to cranial defects, such as traffic accidents, falling objects, cranial surgery and so on, which may injure the skull and lead to cranial defects. Once a cranial defect occurs, it is more dangerous. First of all, the defect area may collapse or bulge, the skull appearance is very unattractive, and it is easy to be hurt by the outside world, and it will also cause a series of skull defect syndrome. The intracranial pressure is unstable, and various life activities in the skull may be disturbed, which may manifest as headache and dizziness. In addition, patients have fear of pulsation, expansion and collapse of the defect area, as well as fear of sunlight, fear of vibration and even fear of noisy sound. It may also cause lack of concentration and memory loss, and some patients may be depressed, tired, reticent and have low self-esteem. Therefore, once a cranial defect occurs, a cranial repair should be performed in time to regain the stability of the cranial cavity environment and to guarantee the normal functioning of all neurological activities. Cranial bone repair is to replace the defective cranial bone with a special medical material to repair the defective bone window, because after all, it is a foreign body implanted in the body, so in some cases there may be a rejection reaction. What is the probability of rejection of cranial bone repair? This rejection probability is highly dependent on the repair material used. For example, materials such as titanium mesh are not histocompatible and can cause rejection, so the probability of rejection is higher; however, the Aviation General Hospital currently has a new polyetheretherketone PEEK material, which is very histocompatible and does not cause rejection. In addition, it is excellent in elasticity, strength, stiffness, thermal insulation and other aspects of performance, comparable to autologous cranial bone, gradually by the neurosurgical community.