Abstract: It is of great significance to monitor radiation dose and standardize radiation protection of differentiated thyroid carcinoma (DTC) patients after ¹³¹I treatment.It can protect patients and the surrounding people from radiation risks.The present study showed that the adverse reactions can be alleviated and controlled effectively in DTC patients after ¹³¹I treatment.The radiation dose of the surrounding people can be in line with the international radiation protection regulations, as long as the related laws and regulations of radiation protection in ¹³¹I treatment can be strictly obeyed, as well as the radiation dose is monitored and the right guidance and instructions are given to the patients, staff and family members.