There is no substitute for the role of the skull in the human body, and it is only with the strong protection of the skull that the brain tissue can function normally. However, accidents are everywhere in life, such as traffic accidents, falling objects, etc. can lead to cranial defects. Cranial defect has a great impact, so patients should not be careless. The integrity of the cranial cavity is severely damaged after cranial defect, and the intracranial environment and intracranial pressure become very unstable, which directly affects the circulation of cerebrospinal fluid and blood in the cranium, and the normal operation of brain nerve function may also be affected, thus causing a series of cranial defect syndrome. For example, patients may feel dizzy and headache, numbness and weakness of limbs, easy to be irritable, and also have vision, hearing and smell impairment, and in serious cases, epilepsy may be induced. Cranial defects also seriously affect the aesthetic appearance, and patients will have a greater psychological burden and become more inferior and depressed in the long run. In addition, without the protection of the skull, the brain can be threatened at any time, especially if it is hit by sharp objects, which can injure the brain tissue and even threaten the life. The damage caused by cranial defects should not be underestimated, and timely cranial repair surgery is the key. The current material used for skull repair is PEEK, which is a better material for skull repair because of its 3D printing technology and similarity to autologous skull bone.