Abstract: Objective To explore the clinical effectiveness of radiofrequency thermocoagulation at different temperatures for severe primary trigeminal neuralgia guided by 3D digital subtraction angiography (DSA). Methods A total of 57 patients with severe primary trigeminal neuralgia involving the maxillary branch, who were treated at Department of Pain and Interventional Vascular Surgery, Huai'an Huai'an Hospital from January 2017 to June 2020, were included in the study. They were divided into two groups: a study group (n=30) and a control group (n=27). The study group underwent radiofrequency thermocoagulation at 90 ℃, while the control group was treated at 75 ℃. Their preoperative general data and follow-up information were collected. Both groups were compared for pain relief effectiveness and recurrence rates. Regression analysis was performed to investigate the factors influencing postoperative recurrence after radiofrequency thermocoagulation for primary trigeminal neuralgia. Results The immediate postoperative pain relief rates were 96.7% in the study group and 92.6% in the control group, without statistical differences (P＞0.05). The pain relief rate at discharge was 100% in both groups. Recurrence began at postoperative 13 month, with a median recurrence time of 20 months. In the study group, 6 patients (20%) experienced recurrence, with a median recurrence time of 22 months. The recurrence rates at postoperative 13 months, 2 years, and 3 years were 0, 13.3%, and 20%, respectively. In the control group, 13 patients (48.1%) experienced recurrence, with a median recurrence time of 19 months. The postoperative recurrence rates at 13 months, 2 years, and 3 years were 7.4%, 25.9%, and 48.1%, respectively, with statistical differences between the two groups (P＜0.05). The radiofrequency thermocoagulation temperature was identified as a factor influencing postoperative recurrence (P＜0.05). The study group had a higher incidence of facial swelling and sensory reduction compared with the control group, without statistical differences (P>0.05). No cases of diplopia, facial paralysis, cerebral hemorrhage, or death were observed in either group. Conclusions Radiofrequency thermocoagulation at 90 ℃ for severe primary trigeminal neuralgia is safe and effective. Its short-term efficacy is comparable to that of 75 ℃, but its long-term efficacy is superior.