There are many causes of cranial defects in life, such as: trauma, brain diseases, intracranial decompression, etc. All of them may lead to cranial defects. Once a cranial defect is caused, the location of the defect will lose the protection of the cranial soft tissues by the cranium, which will bring threats to the life and health of the patient. Therefore, patients with cranial defects should have cranial bone repair surgery in time to better protect their lives and health. Cranial repair surgery belongs to a mature surgery in neurosurgery, of course any surgery has risks, and cranial repair surgery is crucial for material selection to avoid rejection reactions, such as titanium mesh. PEEK is a new material that is resistant to compression, smashing and high temperature, and does not affect MRI at all. Due to the precise three-dimensional reconstruction technique, the bone plate is seamlessly embedded in the defective bone window and blends in with the autologous skull. In our patients who received PEEk cranial bone repair, the MRI revealed that the PEEK bone plate completely overcame the metallic artifacts and that the MRI images were very clear and the structure was very well defined, to the patient’s satisfaction.