What do I need to pay attention to before cranial repair surgery? The first is the degree of recovery of the brain tissue, this we can look through the direct vision of the cranial defect area is dilated or depressed, if it has been in the dilated, it means that the brain this damage is not completely repaired, generally we have to look at the localized if the depression before the operation. Secondly, we need to look at the healing degree of the incision around you, there is no redness, no edema, no ulceration, only when the incision has healed completely well, we can have the possibility of the next step in the treatment of cranial defects. Secondly, whether there is epilepsy or paralysis of limb movement before surgery, this is a series of evaluations that we have to do before surgery. If we want to do surgery, surgery requires certain criteria, that is to say, we need to have no contraindications to surgery, such as no serious cardiopulmonary impairment, no serious coagulation disorders, no serious anemia, and so on. The first postoperative attention is to pay attention to the possibility of an intracranial hematoma and infection in the short term, and the second is to prevent the occurrence of epilepsy and hydrocephalus after surgery. The third one is some effects in the long term, the long term includes this kind of chronic rejection, including some irritation to the body and to the skin. But with the development of new materials, new material technology is getting better and better, we find that the histocompatibility is also getting better and better. Currently, we believe that the PEEK material has the best histocompatibility, which is better than titanium plate, better than Plexiglas and better than bone cement.