Abstract: Objective To investigate the clinical efficacy and adverse reaction of ultrasound-guided percutaneous microwave ablation (PMWA) in the treatment of thyroid nodules, and provide a theoretical basis and guidance for the clinical treatment. Methods Total 128 patients with benign thyroid nodules in our hospital from January, 2015 to August, 2016, were enrolled and randomly divided into control group (n=64) and study group (n=64). The control group was treated with conventional surgical resection, while the study group received ultrasound-guided PMWA. The success rate, nodular reduction and incidence of complication were compared between the two groups. Results The success rate of the control group was 99. 13%, and of the study group was 96. 12%, the other 3. 88% received the secondary ablation and also reached the goal of elimination. The number of thyroid nodules decreased with the time of microwave ablation, 98 nodules disappeared completely in 12 months after the operation. The mean volume of nodules decreased gradually with the extension of time. After one month, three months, six months and twelve months, the nodules reduce by 17. 65%, 40. 69%, 72. 55% and 88. 73%, respectively. The total adverse effect was 31. 25% in the control group, which was significantly higher than that in the study group (4. 69%). Conclusion Ultrasound-guided PMWA for thyroid nodules can achieve the similar therapeutic effect of surgical resection, effectively prevent the damage of surgery to the patients and reduce the incidence of adverse reactions, it is worth further clinical research and application, which will be a new approach for patients with contraindications to surgery