With the increasing incidence of thyroid cancer, people are more and more concerned about the treatment of thyroid cancer. At present, the most reasonable treatment for most well-differentiated thyroid cancer and its metastases is the “triple” treatment of total thyroidectomy + 131 iodine therapy + oral thyroid hormone. Although the “three-in-one” treatment plan for differentiated thyroid cancer has been increasingly accepted by the industry, different scholars still have different opinions on the scope of resection for different lesions. Most physicians advocate total thyroidectomy to remove as much of the thyroid gland as possible, but only if the parathyroid glands and the laryngeal nerve are protected. In fact, total thyroidectomy is associated with high complications and is extremely unnecessary, as high doses of radioactive iodine are effective in removing residual functional thyroid tissue from the neck after surgery. Another consideration in favor of total thyroidectomy is that 131I is more effective in removing postoperative residual thyroid because of the small number of residual thyroid glands and the small dose of 131I required. In addition, total thyroidectomy causes hypothyroidism and TSH elevation, provides early detection of functional metastases, and offers early treatment options. It is now recognized that the principle of surgery is to remove as much cancerous tissue as possible and to remove lymph nodes in the neck where metastases may have occurred. It is difficult to completely remove the thyroid gland surgically in order not to damage the parathyroid glands and the recurrent laryngeal nerve. Therefore, after surgical removal of the thyroid gland, the residual thyroid tissue should be promptly removed using 131I and then thyroid hormone replacement therapy should be given to reduce the recurrence rate of thyroid cancer.