Currently, cranial defects are one of the more common cranial disorders in neurosurgery. Various reasons and risks in life may lead to skull defects, for example, traumatic brain injury is a very common cause of skull defects, some of them are due to traffic accidents, some are due to safety accidents in the production of traumatic brain injury, and some may be due to fights and fights and lead to traumatic brain injury, which may ultimately lead to skull defects. No matter what the cause, a skull defect should be repaired in a positive and timely manner. If the defect is not repaired, it will have an adverse effect on the health of the body and may even be life-threatening. Some patients may experience frequent chronic pain, some may experience frequent dizziness, and some may even affect functions such as limb movement, speech, vision, hearing, etc. It may also cause mental inferiority complex. There is also a lack of hard cranial bone protection, if by external forces, the brain tissue is easily injured, or may be life-threatening. Therefore, timely repair of the skull is very necessary. So when is the best time for skull repair after traumatic brain injury? Generally speaking, if the wound is relatively clean and open skull defect, the skull can be repaired in one stage; while if it is closed craniocerebral trauma or cerebral hemorrhage, due to intracranial hypertension and the skull defect caused by large bone flap decompression surgery, it usually takes 2-3 months before repair surgery. In addition to the timing of the repair, the repair material is also very important. At present, the ideal cranial bone repair material is polyether ether ketone PEEK material, PEEK material is currently the closest material to the human skull, non-rejection, non-infection, high postoperative comfort, good protective performance, has become the latest trend of cranial bone repair material.