Not doing iodine treatment after thyroid cancer surgery may be dangerous, but not all patients are suitable for iodine 131 treatment. Doing iodine treatment after thyroid cancer surgery can effectively prevent metastasis and recurrence of cancer cells. This is because when the tumor of thyroid cancer is relatively large, it is easy to invade the surrounding tissues and organs, such as lymph nodes, trachea, esophagus and so on, and it is necessary to do iodine 131 treatment after surgical treatment. If thyroid cancer does not do iodine treatment after surgery, it is easy to have distal metastasis, such as metastasis to lungs and bones. If the tumor of thyroid cancer is relatively small, after the professional oncologist analyzes and evaluates the condition, conservative treatment can be taken, and iodine 131 treatment is not considered first, but regular review is needed to adjust the treatment plan at any time according to the change of condition. It should be noted that iodine 131 treatment is applicable to patients over 45 years old with papillary adenocarcinoma, follicular adenocarcinoma, such as multiple cancer lesions, locally invasive tumors or distant metastases. Whether to do iodine treatment specifically after thyroid cancer surgery, it is recommended to combine with the treatment plan of the attending doctor to make the right choice.