Cranial defects in some people are children, children with small cranial defects, some of the clinical observation can form islands of bone, and later may form thin pieces of bone, is a chronic process. It is a chronic process. The degree of localization in the later stage depends on the individual’s physique, part of the children if the defect is observed for a long time after the defect, and the small area of the defect is likely to grow well. However, there is no systematic evidence for large defects. So even in developing children, cranial defects may not grow well on their own. Patients should plan for the worst and not take any chances. Choice of material for cranial repair: the material is usually chosen from peek, which has better histocompatibility. It is more comfortable and the thickness is strengthened. It is similar to human skull. Especially for children patients, it can better adapt to the growth and development of human autogenous cranium. And it will have a lower rate of infection and rejection. Importantly, polyether ether ketone material is a material that can be three-dimensionally plasticized, and it can be three-dimensionally customized according to different patients’ conditions, which can really restore the physiological structure of the skull perfectly. Purpose of cranial bone repair: patients with cranial defects often have a heavy burden of thought such as insecurity, and can cause headaches, dizziness, fear of vibration and other syndromes. The longer the cranial defect, the higher the incidence of cranial defect syndrome and secondary brain damage. Therefore, cranial repair is necessary for safety reasons.