Objective: To investigate the effect of Jianpi Xiaoying Decoction combined with Youjiale on thyroid hormones, thyroid autoantibodies and CD4+CD45RO+ memory T cells in patients with Hashimoto's thyroiditis (HT) due to spleen deficiency. Methods: A total of 60 patients with HT who were treated in our hospital from May 2020 to November 2021 were selected and randomly divided into the control group (treatment with Youjiale, 30 cases) and the study group (Jianpi Xiaoying Decoction combined with After 12 weeks of treatment, the clinical efficacy was observed in both groups, and the changes of TCM syndrome scores, thyroid hormones, thyroid autoantibodies and CD4+CD45RO+ memory T cells were compared between the two groups before and after treatment. Results: The clinical total effective rate of the study group was higher than that of the control group (P<0.05). Thyroid-stimulating hormone (TSH) level, total score of TCM syndrome, percentage of CD4+CD45RO+ memory T cells in peripheral blood mononuclear cells (PBMC), thyroglobulin antibody (TGAb), thyroid peroxide in the study group after treatment The enzyme antibody (TPOAb) was lower than the control group (P<0.05), and the levels of free triiodothyronine (FT3) and free thyroxine (FT4) were higher than those in the control group (P<0.05). Conclusion: The treatment of HT patients with spleen spleen deficiency type combined with Jianpi Xiaoying Decoction can improve their thyroid hormone levels, regulate the level of thyroid autoantibodies and the percentage of CD4+CD45RO+ memory T cells in PBMC, and further improve the clinical efficacy. [ABSTRACT FROM AUTHOR]