Provided in the present invention are polypeptides having integrin affinity and binding ability, and the polypeptides can be used for preventing and treating rheumatoid arthritis. In particular, the polypeptides are: polypeptide I: Ala-Cys-Asp-Cys-Arg-Gly-Asp-Cys-Phe-Cys-Gly-Gly-Gly-Gly-Ile-Val-Arg-Arg-Ala-Asp-Arg-Ala-Ala-Val-Pro polypeptide II: Ile-Val-Arg-Arg-Ala-Asp-Arg-Ala-Ala-Val-Pro-Gly-Gly-Gly-Gly-Arg-Gly-Asp polypeptide III: mPEG-SC