To investigate the effect of Erxian decoction combined with euthyrox on inflammatory factor and immune function in patients with hypothyroidism, and to analyze the possible mechanism of action of combined treatment. Methods:A total of 148 patients with hypothyroidism in our hospital were divided into control group and observation group by random number table, with 74 cases in each group. Control group was given euthyrox, while observation group was given Erxian decoction combined with euthyrox. After 4-week treatment, the inflammatory factor, immune function, and clinical efficacy were compared between the two groups. Results:The effective rate of observation group was 97.30%, which was higher than 87.84% of control group (χ2=4.812, P<0.05); The tumor necrotic factor-α (TNF-α), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) content in observation group were lower than that in control group (t=3.946~4.839, P<0.05); After 4-week treatment, the ratio of CD3+, CD4+T cell in observation group increased compared with control group, while the ratio of CD8+, CD16+T cell decreased compared with control group (t=6.322~11.029, P<0.05, P<0.01). Conclusion:Erxian decoction combined with euthyrox for patients with hypothyroidism can increase clinical efficacy, decrease the levels of inflammatory factor and improve immune function.