Thyroid cancer (nail cancer for short) is currently on the rise. Among nail cancers, 80% are differentiated nail cancers. Differentiated nail cancer is a kind of cancer with better prognosis and possible cure. However, its disadvantage is that it is easy to recur and once recurred, it is not easy to be completely cured. According to a study, the recurrence rate of differentiated nail cancer is 33% for surgery alone, 15% for surgery + thyroxine tablets, and less than 3% for surgery + radioiodine therapy + thyroxine tablets. If the lesion has broken through the envelope or invaded the surrounding tissues or has lymph node metastasis during surgery, it should be removed as much as possible, and radioactive iodine therapy should be given routinely after surgery. In particular, radioactive iodine treatment should be performed in a hospital with a nuclear medicine ward and not outside the hospital.