Giant intracranial aneurysms have always been remain the most difficult cerebrovascular lesions to treat, especially for giant cavernous carotid aneurysm (CCA). The treatment of giant CCA is a greatest challenge for neurosurgeons. Surgical clipping morbidity and mortality rates are relatively high, and endovascular embolization also have a high complication. The authors reported a special 74-year-old female patient who presented with blurred vision and double vision for 3 years, a giant CCA was found by digital subtraction angiography and computed tomography angiography. In the end, the CCA was treated using high-flow external carotid artery to middle cerebral artery bypass and clipping distal of the aneurysm. This technique and treatment was successful and without ischemia and neurologic sequelae. Also, their long-term follow-up demonstrated that brain tissue perfusion was better than before. Based on the literature reviewing, this technique might be an alternative strategy for intracranial giant unruptured aneurysms, especially for not suitable for direct clipping or with a high risk for endovascular embolization.