Cranial defect is a very common clinical disorder in neurosurgery. There are many risk factors in life that may lead to cranial defects, such as traffic accidents, production safety accidents, falling objects, falls from height, etc., and craniocerebral trauma after decompression surgery, or craniotomy due to cranial diseases (such as cerebral hemorrhage, intracranial tumors, cranial lesions, etc.), which cannot immediately return the bone flap, these cases often leave cranial defects. Cranial defect syndrome Cranial bone plays an important role in supporting and protecting the brain, head and facial organs, and even in the smooth operation of the whole body. So what are the syndromes of cranial defects? Many cranial defects destroy the integrity of the cranial cavity, the intracranial environment and intracranial pressure become unstable, which will affect the circulation of cerebrospinal fluid and blood circulation in the cranium and affect the normal operation of brain nerve function, thus producing a series of cranial defect syndromes. Specific manifestations may include dizziness and headache, unfavorable limbs, numbness and weakness, depressed mood, irritability, irritability, unexplained discomfort and various mental disorders, and some patients may have symptoms such as impaired vision, hearing impairment, loss of smell, etc. More serious cases may have seizures. Other hazards of cranial defects In addition to these syndromes, cranial defects may also have cosmetic, safety and security, and psychological trauma problems. After skull defect, the scalp will be obviously collapsed, or some patients will have scalp expansion, which will affect the aesthetic appearance; lack of hard skull protection, the brain will be at risk, and may be injured by external invasion, sharp object impact, and may even be life-threatening; in addition, skull defect will cause psychological trauma and blow to patients, and many patients will have self-containment, low self-esteem, do not like to go out, do not want to see people, etc. Many patients will have self-imposed, low self-esteem, do not want to go out, do not want to see people, etc. Therefore, patients with cranial defects should undergo cranial bone repair in a timely manner. Our team is currently working extensively on cranial bone repair, using the new special polymer material polyether ether ketone PEEK as the cranial bone repair material, and constantly improving and upgrading 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 bone repair and plastic surgery, which can achieve the organic unity of anatomical integrity, functional perfection and aesthetic appearance. We have achieved good results.