<p>This study aimed to evaluate the clinical efficacy of intracranial and extracranial vascular bypass surgery for patients with nasopharyngeal carcinoma (NPC) with internal carotid artery invasion after radiotherapy. Sixty-five patients with internal carotid artery blowout syndrome admitted to our center between May 2018 and June 2020 were retrospectively analyzed, including 48 males and 17 females, The patients were divided into two groups: (an intracranial and extracranial vascular bypass group and an internal carotid artery embolization group)and followed up for 1–23 months. We compared the incidence of stroke events and the mortality rate between the two patient groups. In the intracranial and extracranial vascular bypass group, four patients (4/22, 18.2%) died postoperatively due to bleeding and pulmonary infection. Additionally, three patients (3/22, 13.6%) developed new-onset neurological disorders during follow-up, with two of them experiencing right limb hemiplegic paralysis. In the internal carotid artery (ICA) embolization group, six patients (6/43, 13.9%) died within 3–5 months postoperatively due to epistaxis, cerebral hemorrhage, and infectious pneumonia. Furthermore, 16 patients (16/43, 37.2%) developed new-onset neurological disorders during follow-up, with one of them experiencing hemiparesis. Statistical analyses revealed a significant difference in the incidence of new-onset neurological function abnormalities after treatment between the intracranial and extracranial vascular bypass group and the internal carotid artery embolization group (<i>P</i> = 0.039), indicating that bypass is more effective. Intracranial and extracranial vascular bypass surgery following internal carotid artery embolization produced better outcomes in patients with positive balloon test occlusion (BTO) results and reduced the incidence of ischemic events and new-onset neurological disorders after embolization.</p>