Abstract： Objective： To observe the curative effect of the therapy of Fuzheng Xiaoying Decoction combined with Levothyroxine Sodium Tablets on hashimoto thyroiditis (HT) and its effects on serum inflammatory factors. Methods： A total of 90 HT patients were selected and divided into the observation group and the control group according to the random number table method，with 45 cases in each group. The control group was given Levothyroxine Sodium Tablets for treatment，and the observation group was additionally treated with Fuzheng Xiaoying Decoction based on the treatment of the control group. The clinical effects and incidence of adverse reactions，and the changes in traditional Chinese medicine (TCM) syndrome scores，thyroid volume，and levels of laboratory parameters [interleukin-6 (IL-6)，interleukin- 12 (IL-12)， tumor necrosis factor- α (TNF- α)， free triiodothyronine 3/free triiodothyronine 4 (FT3/FT4)， thyroid stimulating hormone (TSH)， thyroid peroxidase antibody (TPOAb) and thyroglobulin antibodies (TGAb)] were compared before and after treatment between the two groups. Results：After treatment，the TCM syndrome scores in the two groups were decreased when compared with those before treatment (P＜ 0.05)，and the TCM syndrome score in the observation group was lower than that in the control group (P＜ 0.05). The total clinical effective rate was 93.33% in the observation group and 75.56% in the control group， the difference being significant (P＜0.05). After treatment， the thyroid volume in the two groups was reduced when compared with that before treatment (P＜0.05)， and the thyroid volume in the observation group was less than that in the control group (P＜0.05). After treatment，the levels of IL-6，IL-12，TNF- α，TSH，TPOAb and TGAb in the two groups were decreased when compared with those before treatment (P＜0.05)，and the levels of FT3 and FT4 were increased when compared with those before treatment (P＜ 0.05)；the levels of IL-6，IL-12，TNF- α，TSH，TPOAb and TGAb in the observation group were lower than those in the control group (P＜0.05)，and the levels of FT3 and FT4 were higher than those in the control group (P＜0.05). During treatment，adverse reactions occurred in the two groups，and they recovered after rest. Conclusion：The therapy of Fuzheng Xiaoying Decoction combined with Levothyroxine Sodium Tablets can enhance the clinical effect on HT patients，which can inhibit the levels of serum inflammatory factors， reduce the inflammatory responses and mitigate the clinical symptoms.