A thyroid nodule is a scattered lesion that can be clearly demarcated on imaging from the surrounding thyroid tissue. Thyroid nodules can be palpable in about 5% of the normal population and can be detected by ultrasound in 19% to 67% of cases, but only 5% to 15% of thyroid nodules are malignant. Since medication is virtually ineffective for thyroid nodules, surgical excision has become the conventional treatment for those nodules that require treatment. Although there have been significant advances in thyroid surgery in the last two decades, the application of refined perineural dissection techniques has resulted in good protection of the recurrent laryngeal nerve and parathyroid glands, and the development and application of various modern surgical instruments has made thyroid surgery “bloodless” and “minimally invasive”. “However, conventional surgery still has the disadvantages of greater trauma, aesthetic impact on the anterior neck scar, and postoperative hypothyroidism. And when thyroid nodules recur, the complications of re-operation will be greatly increased. The lumpectomy thyroid surgery, which was called “minimally invasive” in China a few years ago, only redirects the surgical scar on the neck to the chest, and is more traumatic and has more complications than conventional surgery, and is actually just a “cosmetic” surgery without a scar on the neck. In contrast to the above treatment methods, ultrasound-guided percutaneous microwave and radiofrequency ablation treatment of thyroid nodules has become a “minimally invasive” treatment for thyroid nodules in the true sense of the word because it is highly targeted, less invasive, more reliable and does not require general anesthesia. Ultrasound, CT, MRI image guided radiofrequency, microwave and laser thermal ablation for the treatment of occupying lesions in various organs is a hot research topic in tumor treatment today, and is mainly used for the treatment of liver, lung, kidney and thyroid tumors. For example, the 2011 edition of China’s “Diagnostic and Treatment Standards for Primary Liver Cancer” states that ablation therapy can be applied to patients whose tumors have a maximum diameter of ≤3 cm. For thyroid nodules, laser ablation and radiofrequency ablation were firstly applied to treat recurrent thyroid cancer after surgery by Pacella et al. in 2000 and Dupuy et al. in 2001, respectively. In China, microwave and radiofrequency ablation have been applied to treat benign thyroid nodules and some micro papillary thyroid cancers since 2005 by Shanghai Changzheng Hospital and 301 Hospital of the People’s Liberation Army. The principles of microwave and RF ablation are more or less the same, but microwave ablation produces higher energy, faster and shorter ablation time, and less pain for patients, so it is more widely used in China. Microwave ablation treatment of thyroid nodules is performed in front of the neck after local anesthesia, under the guidance of ultrasound positioning, a 1.6 mm thick water-cooled microwave needle is percutaneously punctured into the thyroid nodules to start the emission of microwaves, through the high temperature effect of inactivation of the lesion, the tissue undergoes the evolution of sterile inflammation – necrotic tissue fibrosis – fibrous tissue absorption process, ultrasound observation of the nodules gradually become smaller, until finally absorbed. Since the puncture needle is very thin, it will not leave scars in the neck, the puncture path is less traumatic, and real-time ultrasound monitoring of the treatment range can avoid over- or under-treatment, which can protect the normal thyroid tissue to the greatest extent, and also protect the function of the thyroid gland to the greatest extent, which well reflects the minimally invasive nature of thyroid nodule treatment. The main indications for microwave ablation treatment of thyroid nodules are: ① Fast-growing benign thyroid nodules, including nodular goiter, thyroid adenoma, etc. It is especially suitable for those who do not want to leave scars on their necks and those who are afraid of hypothyroidism and take medication for a long time. In addition, for the presence of cystic components of the thyroid nodules, because of the satisfactory postoperative clinical results, it is a good indication for microwave ablation. ②Recurrence of thyroid nodules after surgery, due to the greater risk of reoperation of the thyroid, microwave ablation becomes the best choice for recurrent lesions of the residual gland that must be treated. ③For postoperative recurrent thyroid cancer, although surgery is the preferred treatment for thyroid cancer recurrence, microwave ablation can be chosen for its cancerous lesions and associated lymph nodes if the patient has a higher risk of surgery or refuses surgical treatment. Some scholars believe that thermal ablation is still effective in treating liver cancer and lung cancer less than 75px, and micro papillary thyroid cancer (i.e. papillary cancer <25px) is of low malignancy, so microwave ablation can be chosen and followed up. Since the thyroid gland is small and adjacent to important structures such as trachea, carotid artery and laryngeal nerve, microwave ablation may cause complications, including voice change, anterior cervical hematoma and skin burns, etc. The incidence is about 3%, which can be relieved by itself. The main preventive measures are: ① Strictly grasp the indications, the nodules close to the thyroid "danger triangle", should be mobilized for routine surgery. The nodules to be ablated should be isolated from the important blood vessels and nerves through the technique of "isolation belt" injection. Although the minimally invasive nature of microwave and radiofrequency ablation for thyroid nodules is outstanding and its effectiveness and feasibility have been confirmed, the clinical application of this technology is relatively short, and we still need to make continuous efforts to lay the foundation for better application of this technology.