Abstract: Objective: To explore the safety and clinical effects of the percutaneous microwave ablation(MWA) guided by ultrasound in the treatment of benign thyroid nodules.Methods: Thirty-nine patients with 58 benign thyroid nodules were treated with the percutaneous MWA guided by ultrasound.The nodule shrink and occurrence of complications after MWA were observed.Results: Fifty-eight benign thyroid nodules in 39 cases were treated with MWA,54 nodules were completely ablated at one-time,the complete ablation rate of which was 93.1%,and 4 nodules were completely ablated after MWA again.Compared with before treatment,all nodules volume shrinked after six months of following up.Twenty-five cured.The nodule shrinkage rate more than 50% in 8 cases,25% to 50% in 4 cases and less than 25% in 2 cases were found.The postoperative mild transient voice hoarse in 2 cases,lesion side gumand shoulder pain in 4 cases and no secondary hypothyroidism and serious complications were identified.Conclusions: The treatment of benign thyroid nodule with percutaneous MWA guided by ultrasound is effective,safe,less invasion and beautiful,which is worthy of application and promotion under the premise of mastering the indications.