Skull defect is not an uncommon disorder, and we may sometimes be able to see people with partially collapsed heads, which looks very scary. Especially in recent years, traffic accidents and production safety accidents are frequent, as well as some fights and falling objects, which can easily cause serious head trauma and eventually lead to cranial defects. The skull defect is a great harm to the patient and will have many adverse effects on the body. Some patients will have headache and dizziness, some will have fear and low self-esteem, and it may also cause lack of concentration and memory loss, and some patients may show depression, fatigue and oligophrenia. In addition, some patients report that the skull defect bulges after a period of time. In this case, there are generally two reasons: on the one hand, it is because there is an open bone window after the skull defect, which provides the basis for bulging; on the other hand, there may be some lesions in the skull. In these patients with bulging cranial defects, some of them can subside on their own, while others need to be disposed of by neurosurgeons. However, all of these require timely cranial repair. Careful consideration should be given to the choice of a hospital that specializes in the management of brain bulges and cranial repair and has advanced experience in this field. In addition, the choice of cranial repair material is also important, and polyetheretherketone PEEK is a very advanced cranial repair material. The performance of this material is excellent, very close to the performance of the human skull, good histocompatibility, no adverse reactions after surgery, good protection, and can achieve very ideal repair results.