Abstract: Objective By calculating the dose equivalent to patients with Graves' disease by ¹³¹Ⅰ therapy, to evaluate the radiation safety of the individuals around the patients. Methods All patients had heed achieved the practical measure and follow-up, there attained the percentage of thyroid ¹³¹Ⅰ uptake, the ¹³¹Ⅰ dose, the duration of constrained social activity, and practical measure the effective dose equivalent rate and contact exact time with others, and compared the exposure dose to the individuals with the simplistic formula and practical measure accumulating dose calculating methods. Results For all patients with Graves' disease, the exposure doses to the individuals were not likely to exceed normal, Practical measure accumulating doses is higher than the simplistic formula calculating ones (t=3.953, P<0.001). When the adults' contact restricted time with the patients not exceed 6 days, practical measure accumulating calculating doses is higher (t=3.894, P<0.001), but exceed 6 days and enfant (commonly restricted), there were no difference between the simplistic formula calculating doses and practical measure accumulating calculating ones (t₁=0.910, t₂=1.705, respectively P>0.05). Conclusions All patients with ¹³¹Ⅰ therapy were safety to the individuals surrounding to the patients, practical measure accumulating doses is better and more practical.