When thyroid cancer recurs three years after surgery, it is necessary to determine whether it is a recurrence of residual thyroid cancer in the neck, a metastasis in the lymph nodes of the neck, or a recurrence of metastasis in other distant tumors in the body. In case of differentiated thyroid cancer, the thyroid gland itself has not been excised, and it is pathologically confirmed that the thyroid cancer has recurred, the main purpose is to operate again to excise the residual thyroid gland and clear the lymph nodes in the corresponding area. If the lymph nodes in the neck have recurred and the first surgery has not been done in a standardized way, you can operate again. If a standardized clearance was done the first time, a supplemental clearance may be required. If there are metastases in other parts of the body, such as lung metastases or bone metastases, nuclear vector therapy, iodine-131 therapy, is done. In case of differentiated thyroid cancer, endocrine therapy is also done, the most common one is eugenol suppression therapy. Some people with recurrent lesions do not absorb iodine and can take targeted therapy. Various measures should be combined to determine the specific situation of recurrence and then do the treatment accordingly.