Abstract： Objective： To observe the effect of modified Zhizi Qinggan Decoction combined with Methimazole for hyperthyroidism. Methods：A total of 120 cases of patients who had hyperthyroidism and admitted to Wenling Traditional Chinese Medicine Hospital Affiliated to Zhejiang Chinese Medical University from January 2019 to June 2022 were retrospectively selected and divided into the control group and the observation group according to different treatment methods， with 60 cases in each group. The control group was treated with Methimazole Tablets， and the observation group was treated with modified Zhizi Qinggan Decoction and Methimazole. Both groups were treated for two months. Traditional Chinese medicine (TCM)syndrome scores， indicators of thyroid function， and quality of life were compared between the two groups before and after treatment. Clinical effects and the incidence of adverse reactions were evaluated. Results：The total effective rate was 95.00% in the observation group，higher than that of 83.33% in the control group (P＜0.05). After two months of treatment， TCM syndrome scores and the levels of free triiodothyronine (FT3) and free thyroxine (FT4) in serum in the observation group were decreased when compared with those before treatment (P＜0.05)， and the levels of thyroid stimulating hormone (TSH)， the scores of various dimensions and the total score of the Short Form Health Survey Questionnaire (SF- 36) were increased (P＜0.05)；TCM syndrome scores and the levels of FT3 and FT4 in serum in the observation group were lower than those in the control group (P＜0.05)， and the scores of various dimensions and total score of SF-36 in the observation group were higher than those in the control group (P＜0.05)；there was no significant difference being found in the comparison of TSH levels between the two groups (P＞0.05). There was no significant difference being found in the comparison of the incidence of adverse reactions between the two groups (P＞0.05). Conclusion： Modified Zhizi Qinggan Decoction combined with Methimazole has significant curative effects in the treatment of hyperthyroidism， and can improve thyroid function and quality of life with high safety.