Abstract: Objective To investigate the intervention effect of the traditional Chinese medicine Guomin Decoction (GMJ) on Th2-type atopic dermatitis by inhibiting macrophage inflammation through the JAK1/JAK2-STAT1/STAT3 signaling pathway. Methods 48 BALB/c mice were randomly divided into six groups: normal group (Normal group), model group (Model group), dexamethasone-positive drug group (Dex. group), and Guomin Decoction high, medium, and low dosage groups (GMJ-H, M, and L group), 2 nmol MC903 (Calcipotriene) was repeatedly applied to the right ear of mice to induce the establishment of an AD mouse model, then Observed the scratching frequency of mice, measured the degree of ear swelling and organ coefficient, used HE staining and toluidine blue staining to observe changes in skin lesion morphology and the number of mast cells, detected the content of IL-4, IL-5, IL-33, TSLP, HIS, LTB4, and IgE in mouse serum by ELISA method; determined the content of IL-4, IL-33, and TNF-α in the tissues of the skin lesions of mice by immunohistochemistry method. In vitro, MTT assay was used to detect the effect of Guomin Decoction on the proliferation activity of RAW264.7 cells, Cellular inflammation model was constructed by inducing RAW264.7 cells with 1 μg·mL-1 LPS. The content of NO in the cell culture medium was detected by the Griess method, while the content of IL-6 in the cell culture medium was determined by the ELISA method; Western blot was used to detect the expression of phosphorylated JAK1/JAK2-STAT1/STAT3 proteins in each group of cells. Results Compared with the Model group, the Guomin Decoction intervention in Atopic Dermatitis of mice significantly reduced the number of scratches; ear swelling was significantly reduced; the pathology at the ear lesions was greatly improved; Spleen index was downregulated and thymic index was elevated; mast cell number was decreased; and serum expression of TSLP, IL-4, IL-5, IL-33, IgE, HIS, and LTB4, as well as the skin lesion tissue IL-4, TNF-α, and IL-33 expression levels were downregulated. The results of in vitro experiments showed that the concentration of Guomin Decoction at 23～750 μg·mL-1 had no significant effect on the proliferation activity of RAW264.7 cells. Under the test dose, Guomin Decoction significantly inhibited the expression and release of NO and IL-6, and inhibited the phosphorylation levels of related proteins JAK1, JAK2, STAT1, and STAT3 in the JAK/STAT pathway. Conclusion Guomin Decoction may exert a pharmacological effect on improving the inflammatory response in mice with atopic dermatitis by inhibiting the activation of the JAK-STAT pathway in macrophages.