Most thyroid cancer patients were treated with surgical excision in our clinical. In order to achieve total thyroid ablation, the remaining tissue of thyroid glands was irradiated with radioiodine. The γ-energy of radioiodine was higher than the traditional examination and the drugs used in nuclear medicine, and the dosage of radioiodine was still higher while treatment too. Both for the patient who was treated with radioiodine and the nurse who take care of the patient, it is a new challenge in the world that everyone fears of nuclear energy. It is an important topic to understand how to take care of the patients who was received iodine-131 therapy and how to protect ourselves properly. In this article, we describe the issues that how to take care of the radioiodine-treated patient and try to help our staff easier in their clinical works.