In clinical practice, cranial repair surgery is usually performed around three months after craniotomy, but it must also be evaluated according to the actual condition of the patient, as follows: 1. Performed around two months: Because after craniotomy, there is a possibility of combining chronic subdural effusion or chronic hydrocephalus and other related conditions, if such conditions exist, it is recommended that the patient can undergo cranial repair surgery around two months. 2. About three months: If there is no special condition and it is only a simple cranial defect, cranial repair surgery is usually performed about three months because the soft tissues are not particularly tightly adhered at this time and the separation process is relatively smooth, so it is conducive to the smooth implementation of cranial repair surgery. Therefore, it is conducive to the smooth implementation of cranial repair surgery.