The skull, as the protective shield of the human brain, bears the most important responsibility for life activities. According to statistics, there are more than 3 million patients with cranial defects due to traffic accidents and accidents every year, and cranial defects are the more common sequelae of craniocerebral injury patients after injury and surgery. As the brain tissue loses the shielding effect of the normal skull and is easy to be injured for the second time, and the cranial defect can cause various symptoms and affect the appearance, it is often necessary to carry out cranial bone repair and molding, so that the intracranial pressure can be restored to a normal and stable state as soon as possible to reduce the intracranial pressure due to cranial defects caused by the brain pressure of the daily drastic changes in the brain’s continuous and serious damage and functional impact. Generally, repair surgery is performed after 3 months of cranial defect, in which the pressure at the defect site is not high, and there are no factors unfavorable to the healing of the incision, such as infection and ulceration. Therefore, this is the period for surgery. The ideal material for restoration is PEEK. The three-dimensional reconstruction technology of this material can perfectly restore the physiological structure of the skull according to the patient’s cranial CT data, and accurately fit the defective bone window. In addition, the performance of this material in terms of elasticity, thermal insulation, hardness, stability and other aspects is comparable to the autologous skull, which is a perfect cranial bone substitution material, and does not have a foreign body reaction, and will not affect the interference with the future radiological examination. It will also not affect the airplane ride, security check, etc.. At present, the application of peek this new material has been recognized and highly evaluated by patients and medical experts.