〔Abstract〕 Objective To explore the potential mechanism of usnea in the treatment of rheumatoid arthritis (RA) through network pharmacology and experimental validation. Methods Chemical components and action targets of usnea were retrieved through literature review and drug target prediction website, and related targets of RA were retrieved through disease database. The intersection of the two was taken, and Venny software was used to construct the Venny diagram of usnea and RA targets, and common targets were obtained. The traditional Chinese medicine-active ingredient-target network diagram and protein-protein interaction (PPI) network were constructed. DAVID database was used for gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, and the top 20 signaling pathways of KEGG enrichment analysis were selected. Finally, the RA– fibroblast–like synoviocyte (RAFLS) model was established through experimental verification, and the efficacy and mechanism of RAFLS was verified by using pine tree intervention. Results Through database screening, 11 active components, 308 targets, 513 RA targets and 49 common targets were identified. Among them, the main active ingredients of usnea were pine acid, apigenin, ethyl chlamyate, black tea marin, ground acid and so on. The core targets of RA included tumor necrosis factor (TNF) , signal transducer and activator of transcription 3 (STAT3) , matrix metalloprotein 9 (MMP9) , prostaglandin–endoperoxide synthase 2 (PTGS2) , matrix metalloproteinase 2(MMP2), interleukin-2 (IL-2), mitogen–activated protein kinase 14 (MAPK14), transforming growth factor beta1 (TGFβ1), myeloperoxidase (MPO), MMP1, etc. GO enrichment analysis identified 312 entries associated with RA occurrence, and KEGG enrichment analysis identified 88 pathways, with TNF signaling pathway at the top. Experimental validation showed that compared with the blank group, TNF-α and MMP secretion in the solvent control group were significantly increased, and the protein expression of MAPK was significantly upregulated, with a statistically significant difference (P < 0.05). Compared with the solvent control group, the low, medium and high dose groups of usnea and hydroxychloroquine group could promote apoptosis, and reduce the secretion of TNF-α and MMP, and the MAPK protein expression in the medium, high dose groups of usnea and hydroxychloroquine groups was significantly reduced, with a statistically significant difference (P < 0.05). Conclusion Usnea has the characteristics of multi-component, multi-target and multi-pathway, and its mechanism of action may be completed through the process of cell apoptosis, proliferation and inflammatory response. By inhibiting the generation and release of inflammatory cells, usnea can reduce the destruction of joints to a certain extent, so as to achieve the purpose of treating RA.