〔Abstract〕 Objective To discuss the effect of Bailing Capsule on Hashimoto's thyroiditis. Methods 80 patients with Hashimoto's Thyroiditis Treated in Xinhua District People's Hospital of Pingdingshan City from January 2018 to December 2020 were randomly divided into control group and observation group, with 40 cases in each group. The control group used low iodine diet intervention, and the observation group used Bailing Capsule on the basis of the control group. The curative effect, thyroid [free triiodothyronine (FT3), thyroid stimulating hormone (TSH)] and thyroid size changes were compared between the two groups. Results The total effective rate of the observation group was 92.50%, compared with 77.50% of the control group, the difference was not statistically significant (P > 0.05); After treatment, FT3 in the observation group was lower than that in the control group, and TSH was higher than that in the control group (P < 0.05); After treatment, the thyroid volume of the observation group was smaller than that of the control group, the difference was statistically significant (P < 0.05). Conclusion Bailing capsule can regulate thyroid function in Hashimoto's thyroiditis.