After craniotomy, if the patient is stable, he or she usually wakes up within a few hours. However, if the patient is in a coma before surgery, it is often difficult to predict the exact time of awakening after surgery. In addition, patients with postoperative complications may be in a coma for a longer period of time, and some patients may have difficulty awakening. Craniotomy is a neurosurgical procedure to stop bleeding and remove lesions by opening the skull, and is mainly used to treat craniocerebral trauma, severe cerebral hemorrhage, cerebral hernia, and intracranial tumors. Usually coma due to anesthesia can be awakened within a few hours after surgery. Some patients may have severe cerebral edema or brain hernia after surgery, and the duration of coma can be prolonged accordingly, usually taking about 7 days to half a month, or even longer. In addition, if the patient is in a coma before the operation, it is often difficult to predict the exact time of awakening after the operation. It is recommended that patients choose regular hospitals to undergo craniotomy and be actively treated under the guidance of their doctors.