Many accidents in life often happen unexpectedly, and cranial defects are a common one with an increasing incidence. According to the survey, there are many factors in life can lead to cranial defects, among them, trauma, surgery, the cranial bone itself is more common factors. Factors leading to cranial defects: 1, trauma leads to a larger proportion of cranial defects, ordinary fights and brawls, accidental traffic accidents, production safety accidents, falling objects, etc., in serious cases, cranial injury can occur, resulting in cranial injury. 2.In the clinic, for some patients with cerebral hemorrhage, brain tumor, subdural hematoma, etc., the doctor has to perform debridement decompression in the process of emergency, thus leaving the cranial defect. 3.Some lesions in the skull itself can also cause cranial defect, for example, pediatric growing skull fracture, or cranial osteomyelitis, cranial osteoma, etc. may directly or indirectly cause cranial defect. After cranial defects, the patient’s face value is greatly reduced. PEEK is an ideal material for cranial bone repair and is comparable to human cranial bone in terms of elasticity, strength, thermal insulation, and stability, with a low rate of rejection and infection. The cost of PEEK cranioplasty is determined by the size of the defect and varies from patient to patient.