The skull is a very important organ of the human body, and if it is defective, it should be repaired at the first time. If skull defect is not repaired, it will have a great impact on health, and in serious cases, it may even endanger life and affect life expectancy. If the skull is defective, the brain tissue inside the skull lacks the necessary protection and is easily injured; the skull defect makes the intracranial pressure abnormal, the pressure inside and outside the skull is connected, which is not conducive to the circulation of cerebrospinal fluid, and some functions of the brain tissue may be restricted; in addition, the collapse caused by the skull defect also affects the aesthetics, etc. In cranial defects, the loss of bone flap protection and atmospheric pressure can cause ipsilateral cerebrospinal fluid circulation disorders and decreased cerebral blood flow, leading to potential brain tissue damage. Large skull defects can easily cause deformation and displacement of brain tissue, enlargement of the ventricles, and disturbance of water flow in the brain parenchyma, which affects the production, absorption and circulation of cerebrospinal fluid, resulting in complications such as traumatic hydrocephalus and cerebral bulge. It causes a series of neurological symptoms such as headache, dizziness, local tenderness, irritability, anxiety, fear, unexplained discomfort and various mental disorders in patients. After skull repair, the flow of cerebrospinal fluid improves significantly, cerebral blood flow also increases, and brain injury is improved. Maintaining the integrity of the dura is the protection of the brain, so it is important to choose a suitable material for the repair of cranial defects. The PEEK material can be reconstructed in three dimensions, 3D printed, and highly restored to the physiological structure of the skull, and the material is histocompatible and does not produce any rejection. Very ideal cranial repair material, PEEK material can be perfectly combined with their own cranial bone.