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 bone plays an important role in supporting and protecting the brain, head and facial organs, and even in the healthy and smooth operation of the whole body, so if cranial defect occurs, it will cause serious harm to the human body and lead to a series of cranial defect syndrome. After cranial defect, the integrity of the cranial cavity is destroyed, 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 impaired vision, hearing impairment, loss of smell and other symptoms, and more serious ones may have seizures. In addition to these syndromes, cranial defects may also have cosmetic appearance, safety and security, and psychological trauma. After skull defect, the scalp will obviously collapse, or some patients will have scalp expansion, which will affect the aesthetic appearance. Many patients will have self-exclusion, low self-esteem, reluctance to go out and meet people, etc. Patients with cranial defects should undergo cranial bone repair in time. 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 with excellent performance, 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 plastic surgery, which can achieve the organic unity of anatomical integrity, functional perfection and aesthetic appearance, and achieve good results. We have achieved good results.