Purpose To explore the clinical outcomes and safety of ultrasound-guided microwave ablation (MWA) for treating thyroid benign solid nodules during a three-year follow-up. Methods A total of 53 patients with thyroid benign solid nodules with the largest diameter exceeding 2 cm were treated with US-guided MWA between January 2015 and December 2017. Nodule volume, the cosmetic score, and the symptom scores were evaluated before ablation and 1, 2, and 3 years after the operation. The characteristics of MWA and complications were also evaluated. Results The thyroid nodule volume at each time point after ablation was significantly smaller than that before ablation (p < .05). The Symptom and Cosmetics score were significantly improved (p < .05). Hoarseness was the major complication, with an incidence of 1.89%. The original nodules volume was 7.28 +/- 11.42 mL; the isolating fluid was 34.36 +/- 13.35 mL; the ablation time was 188.77 +/- 89.13s. Conclusions MMA is an effective and safe approach for reducing nodule volume and symptoms in patients with benign thyroid solid nodules.