Abstract： Objective： To observe the clinical effect of modified Haizao Yuhu tang for patients after surgery of thyroid tumor and its effect on the levels of thyroid hormones. Methods：A total of 72 cases of patients after surgery of thyroid tumor were enrolled and divided into the experiment group and the control group according to the random number table method，36 cases in each group. The control group was given levothyroxine sodium tablets， and the experiment group was given modified Haizao Yuhu tang. Both groups were treated for two months. The clinical effect and adverse reactions were observed and compared between the two groups. Before and after treatment， the changes in levels of thyroid stimulating hormone (TSH)，free triiodothyronine(FT3)，and free thyroxine(FT4) were observed and compared between the two groups. Results： The total effective rate was 91.67% in the experiment group， and 66.67% in the control group， the difference being significant(P＜0.05). After treatment， levels of TSH in the two groups were decreased when compared with those before treatment(P＜0.05)，and levels of FT3 and FT4 were increased(P＜0.05)；but the three levels above in the experiment group were higher than those in the control group(P＜0.05). The incidence of adverse reactions was 5.56% in the experiment group，and 22.22% in the control group，the difference being significant(P＜0.05). Conclusion：In the treatment of patients after surgery of thyroid tumor，modified Haizao Yuhu tang has defined clinical effect，which can effectively regulate levels of thyroid hormones and reduce the incidence of adverse reactions.