〔Abstract〕 Objective To evaluate the therapeutic effect of CT/MRI image fusion and usual CT guided percutaneous radiofrequency thermocoagulation of trigeminal semilunar ganglion. Methods The medical information of 88 patients diagnosed with primary trigeminal neuralgia were assembled. In accordance with different imaging guidance means, they were equally divided into the control group(trigeminal semilunar ganglion radiofrequency thermocoagulation with CT guidance) and the fusion group(trigeminal semilunar ganglion radiofrequency thermocoagulation with assistance of CT/MRI image fusion technology) at random. The puncture time, intraoperative discomfort rate, preoperative, intraoperative and postoperative visual analogue scale(VAS) score, Barrow neurological institute(BNI) pain score and postoperative complication rate were contrasted. Results The puncture operation time of the fusion group was shorter than that of the control group(P<0.05); the intraoperative and postoperative VAS and BNI scores, occurrence rate of intraoperative discomfort and postoperative complications in the fusion group were lower than those in the control group(P<0.05). Conclusion In respect of improving therapeutic effect and diminishing intraoperative discomfort and postoperative complications, CT/MRI image fusion technique is superior to CT guidance.