Cerebral hyperperfusion syndrome is a rare but potentially serious complication of cerebral revascularization,which occurs as a result of postoperative refractory hypertension and impaired cerebrovascular autoregulation. Cerebral hyperperfusion after balloon dilatation is prone to occur within the blood supply area of the offending vessel,rarely outside the offending vessel's supply area. This article presented a case of cerebral hyperperfusion syndrome outside the area treated with endovascular surgery.