〔Abstract〕 Objective To use the GEO dataset and bioinformatics techniques, such as LASSO logistic regression, ssGSEA, and WGCNA, to screen for RA diagnostic markers and investigate the impact of earthly flavonoids in Smilax glabra Roxb. on specific immune cell infiltration, to screen for rheumatoid arthritis(RA) diagnostic markers on specific immune cell infiltration and to analyze the combination of flavonoids in Smilax glabra Roxb. and diagnostic markers. Methods The normal control group and RA gene chip were obtained from the Gene Expression Omnibus database. The R 4.3.0 WGCNA software package was used to integrate and analyze the dataset, identify co-expression modules and associated trait information, and screen key modules closely related to RA. LASSO regression analysis was performed using the glmnet package in R to identify characteristic genes for RA. The area under the receiver operating characteristic(ROC) curve was used to evaluate the diagnostic value of the characteristic genes in RA. The gene expression data of the normal control group and RA group were subjected to quantitative immune cell infiltration analysis using the GSVA, limma, and GSEABase packages in R. The chemical components of earthworm flavonoids in Smilax glabra Roxb. were analyzed based on UHPLC-Q-Exactive Orbitrap MS. The correlation between flavonoids and characteristic genes was assessed through molecular docking. Results The LASSO regression algorithm selected 5 characteristic genes(apolipoprotein D, zinc finger and BTB domain containing 16, C-C chemokine receptor type 5, matrix metalloproteinase 1, coronin-1A). The area under ROC curve of all 5 characteristic genes was greater than 0.85, which exhibited positive correlations with various immune cells. Twenty earthworm flavonoids of Smilax glabra Roxb. were identified using UHPLC-Q-Exactive/MS, and Mulberrin and Neobavaisoflavone were well combined with 5 immune characteristic genes. Conclusion Flavonoids compounds of Smilax glabra Roxb. have good combination with RA immune characteristic genes, providing a scientific basis for RA immunomodulation therapy and early diagnosis.