The SP2215 heat resistant alloy has been successfully utilized in the production of superheater/reheater pipes for ultra-supercritical thermal power units operating at temperatures ranging from 620 to 650℃, owing to its exceptional high temperature durability and corrosion resistance. However, there is still a lack of research on the hot deformation behavior of this alloy, which plays a crucial role in determining the subsequent deformation process and final quality of the steel pipe. In this study, a series of hot compression tests were conducted on the alloy using a Gleeble 3500 thermal simulation testing machine at temperatures ranging from 1100 to 1250℃ and deformation rates ranging from 0.01 to 10 s^-1 with a deformation amount of 50%. The influence of different deformation temperatures and rates on the rheological curve and deformation structure of the alloy was investigated. Furthermore, by modifying the rheological curve based on friction and temperature effects, we established thermal deformation Arrhenius constitutive model, Avrami dynamic recrystallization model, and Yada dynamic recrystallization average grain size model for SP22215 alloy. Additionally, Prasad-Murty-Malas hot working maps were constructed for alloys based on various rheological instability criteria. Our findings indicate that as the deformation temperature increases, the degree of work hardening decreases while dynamic recrystallization becomes more likely in SP2215 alloy. Moreover, higher strain rates result in increased flow stress and work hardening rate for this alloy. The lowest degree of recrystallization occurs at a strain rate of 1 s^-1; however, if not properly selected under certain conditions, mixed crystal phenomenon may occur easily in this alloy. Under experimental conditions considered here, the optimal thermal deformation window for SP2215 alloy is found to be between 1200 and 1250℃ with strain rates ranging from 5 to10 s^-1.