Cranial defects are the more common sequelae of craniocerebral injury patients after injury and surgery. As the brain tissue loses the normal skull protection, it is easy to be injured twice, at the same time, cranial defects can cause various symptoms and affect the appearance, therefore, many of these patients need to undergo cranial bone repair surgery, which is designed to make the patient’s intracranial pressure return to normal and stable as soon as possible, to reduce the intracranial pressure due to cranial bone defects and dramatic changes, which will damage the brain function. So, is it okay to mend the skull after craniotomy? Patients with cranial defects will be insecure and have a heavy burden of thoughts in their mind. And cranial defect will cause headache, dizziness, fear of shock and other comprehensive evidence. The longer the cranial defect, the higher the incidence of cranial defect syndrome and secondary brain damage. In order to restore the confinement of the cranial cavity, maintain physiological intracranial pressure stabilization and alleviate the cranial defect syndrome. For cranial defects with a diameter of more than 3 centimeters, without muscle coverage, and without contraindications should be performed after craniotomy for cranial bone repair. Cranial bone repair using the new PEEK material for cranial bone repair surgery, the new PEEK material is currently the best material for cranial bone repair, PEEK material properties and the surrounding bone tissue is closest to the PEEK material at the same time the cranial implant is designed as a wedge-shaped edge of the template, and the patient’s bone window edge can be accurately fit to reduce the patient’s discomfort. Meanwhile, PEEK material is stronger than other repair materials, non-thermal conductive, good self-lubrication, no friction foreign body sensation, perfect and stable molding curve, and no artifacts in CT/MR.