Objective To analyze the clinical characteristics of patients with early hypothyroidism after ¹³¹I therapy and patients with refractory hyperthyroidism. Methods The clinical data of patients with early hypothyroidism after receiving ¹³¹I treatment in three months and patients with refractory hyperthyroidism were retrospectively analyzed in the present study, and the clinical data of them were compared with the patients in the control group. Results A total of 246 patients of hyperthyroidism were included. The thyroid peroxidase antibody (TPOAb) level of the early hypothyroidism group was significantly higher than that of the control group (P<0.05). Patients in the refractory hyperthyroidism group had significantly longer disease course and significantly higher levels of free triiodothyronine (FT₃), free thyroxine (FT₄), thyrotrophin receptor antibody (TRAb), 3 h iodine uptake, and ¹³¹I dose compared with the control group (P<0.05 or 0.01); while thyroid stimulating hormone (TSH) and TPOAb levels of the refractory hyperthyroidism group were significantly lower than those of the control group (P<0.05 or 0.01). Conclusion TPOAb level is closely related to patients with early hypothyroidism after receiving ¹³¹I treatment. Patients with refractory hyperthyroidism have longer disease course and higher levels of FT₃, FT₄ and TRAb.