Stripe rust, a globally widespread disease, stands as one of the most significant threats to wheat cultivation. The 1RS-1BL translocation, known for its robust resistance to both rust and powdery mildew, has historically played an important role in wheat breeding and production. The gene for stripe rust resistance on chromosome 1RS, previously referred to as Yr9, plays an important role in wheat production. In this study, we cloned the stripe rust resistance gene Yr9-b from triticale via genetic mapping and Yr9 from the 1RS-1BL translocation through homologous cloning. Both Yr9-b and Yr9 encode a typical nucleotide-binding leucine-rich repeat (NLR) protein. Through overexpression, transgenic expression driven by its native promoter, and gene knockout, we demonstrated the stripe rust resistance function of Yr9-b. The transgenic wheat plants expressing Yr9-b under its native promoter exhibited strong stripe rust resistance without visible pustules after inoculated with the CYR17 race. Additionally, despite four amino acid differences between Yr9 and Yr9-b, both exhibited identical resistance to stripe rust. However, the two genes lose their resistance when deployed in the field or inoculated with mixed physiological races collected from the field. Our findings provide valuable insights for breeders to strategically incorporate disease resistance genes and lay a foundation for further understanding how pathogenic fungi might evolve to evade recognition by NLR-type proteins.