Can the skull be left unrepaired? Cranial defects must be repaired because the skull is one of the hardest bones in the human body and has a high strength, which can play a strong protective role for the brain and other organs in the head. However, there are still some irresistible factors that may cause damage to the skull, such as falling objects, fighting, traffic accidents, production safety accidents, etc. resulting in craniocerebral trauma, or because of disease and have to remove part of the skull bone flap, which will lead to skull defects. If a defect occurs in the skull, you will be faced with cranial repair. Some patients ask, can the skull be left unrepaired? Usually no. With unstable intracranial pressure, all life activities in the skull may be disturbed, which may be manifested as headache, dizziness, in addition to the patient’s fear of throbbing, bulging and collapsing of the defect area, as well as fear of the sun, fear of vibration and even fear of loud noises. It may also cause inattention, memory loss, and some patients show depression, fatigue, reticence, as well as low self-esteem. So there is still a need for cranial repair. The repair material used in cranial repair surgery is very important. Currently, a new advanced material, Polyetheretherketone, or PEEK, is used clinically for cranial bone repair, and ideal results can be achieved. Three-dimensional molding, precise matching, high biocompatibility, fewer complications, and no interference with medical examination make it an ideal material. PEEK material as the ideal material for cranial bone repair is because PEEK material has very good histocompatibility, basically no rejection reaction, PEEK material has good ray transmittance and does not interfere with all kinds of postoperative medical examinations. In addition, PEEK material in the elasticity, strength, thermal insulation, stability and other aspects of performance are comparable to the human skull, is very ideal for cranial bone repair materials. Through our introduction we understand that cranial defects are not repaired is not possible, so it is recommended that patients and friends to the regular hospital according to their own diagnosis of the disease and then choose the appropriate repair material to repair, regain their health as soon as possible.