Objective: This experiment studied the effect and mechanism of acupoint catgut embedding on rheumatoid arthritis by regulating PD-1 / OX40 signal pathway. Methods: 25 female SD rats were induced with complete Freund's adjuvant to establish rheumatoid arthritis model rats, and then treated with acupoint catgut embedding and drug therapy. The rats were divided into 5 groups: control group, model group, leflunomide group, acupoint catgut embedding group and acupoint catgut embedding leflunomide group. The degree of inflammation was judged by evaluating the arthritis index; The contents of serum IL-6 and IL-8 were detected by ELISA; He staining was used to observe synovitis cell infiltration, smooth abdominal tissue, fibrous tissue, macrophage proliferation and angiogenesis; The contents of PD-1 / OX40 and CD4 cd28-pd-1lowox40 T cell subsets were detected by flow cytometry. Results: except the control group, there were erythema and moderate swelling from ankle to metatarsal or metacarpal joint in each group. After 14 days, there was no significant change in the score of the model group, but the inflammatory factor scores of leflunomide group, acupoint catgut embedding group and acupoint catgut embedding leflunomide group began to decline, and the acupoint catgut embedding leflunomide group decreased the fastest. The contents of IL-6 and IL-8 in serum of model group increased significantly (P < 0.01), and the contents of IL-6 and IL-8 in serum of rats in flutamide group, acupoint catgut embedding group and acupoint catgut embedding leflunomide group decreased significantly (P < 0.01). The synovial tissue of the model group was damaged, with a large number of inflammatory cell infiltration, vascular dilatation and fibroblast proliferation. After leflunomide and acupoint catgut embedding treatment, the inflammatory cell infiltration in the synovial tissue of the model group was significantly reduced and the vascular proliferation was inhibited, and the effect was the most obvious when Leflunomide and acupoint catgut embedding worked together. In the model group, the content of pd-1lowox40 decreased significantly (P < 0.01), the content of CD4 cd28-pd-1lowox40 T cells increased significantly (P < 0.01), and the content of pd-1lowox40 in acupoint catgut embedding group and leflunomide acupoint catgut embedding group increased significantly (P < 0.01) The content of CD4 cd28-pd-1lowox40 T cells in acupoint catgut embedding group and acupoint catgut embedding leflunomide group decreased significantly (P < 0.01). Conclusion: acupoint catgut embedding can improve the symptoms of rheumatoid arthritis, and has the effect of combined treatment with leflunomide. Its mechanism may be related to PD-1 / OX40 signal pathway.