Inclusion Criteria:  Subarachnoid hemorrhage was diagnosed by DSA, CTA or MRA; Within 48 hours; Age > 18 years old; The expected length of stay is more than 7 days; Sign informed consent.  Exclusion Criteria:  There was a history of taking sulfonylureas within 30 days before brain injury; Combined with neurological or mental diseases, including stroke, epilepsy and dementia; Hunt & Hess grade V patients; Severe brain injury (central hernia or hook hernia within 48 hours after admission or after resuscitation) that cannot be solved at present; History of alcohol or illicit drug dependence; Allergic to sulfonamides or glibenclamide tablets; The INR was more than 1.4; Renal insufficiency, history of dialysis treatment or serum creatinine more than 2.5 mg / dl; Liver cirrhosis or severe liver dysfunction (ALT > 2.5 times the upper normal limit or total bilirubin > 1.5 times the upper normal limit); He is taking bosentan tablets to treat pulmonary hypertension; There was a history of G6PD deficiency (faba bean disease); The life expectancy is less than one year; The gastrointestinal tract should not be used; Pregnancy or lactation; History of participating in other drug trials within 30 days; There were clinical conditions that other researchers did not consider to meet the inclusion criteria.