Some people in life may suffer serious cranial trauma for one reason or another, or they may have their own intracranial disorders that require craniotomy to remove a portion of the bone flap, which results in a cranial defect. There are many dangers associated with cranial defects. First of all, the lack of hard shell protection, the brain and other intracranial soft tissues are easy to be directly injured by the outside world, which is very dangerous and may even be fatal; in addition, the loss of part of the skull is also the abnormal intracranial pressure and intracranial environment, which affects the normal operation of intracranial life activities and may cause some neurological symptoms; another point is that the skull defect causes the unattractive appearance of the skull The defective area may be bulging or collapsed. Some people ask what causes the collapse of the skull defect after craniotomy. The collapse of the cranial defect area is normal, because the lack of cranial support, the soft tissue in the skull is directly connected to the atmospheric pressure, which is affected by the atmospheric pressure and is invaginated, of course, some people will cause brain expansion and brain herniation due to some pathological reasons, which are very dangerous, so the cranial defect must be repaired in time. The cranial repair surgery should choose the appropriate repair material, which should meet the physiological standards of human skull, must have high biocompatibility, and need to ensure certain strength and stiffness at the same time, to provide strong enough protection, but also to meet the needs of shaping, to achieve the shape repair cosmetic satisfactory results. At present, the cranial repair material that meets these requirements is polyether ether ketone PEEK material, this polymer material has good biocompatibility, and strength, stiffness, elasticity, stability, thermal insulation and other properties are very close to the autologous cranial bone, is very ideal cranial repair material.