Developing　high-performance　nanocrystalline　SmCo　permanent　magnets　is　essential　for　high-temperature　applications　in　advanced　electromechanical　equipment.　In　this　study,　the　nanocrystalline　anisotropic　Sm0.4Pr0.6Co5　magnets　with　controllable　magnetic　properties　were　achieved　by　adjusting　the　deformation　temperature.　The　Sm0.4Pr0.6Co5　magnet　deformed　at　780　degrees　C　showed　a　high　coercivity　of　19.7　kOe　(1.57　MA/m)　at　300　K　and　of　9.3　kOe　(0.739　MA/m)　at　573　K,　resulting　in　the　temperature　coefficient　of　-0.189　%/degrees　C.　The　magnet　deformed　at　840　degrees　C　exhibited　a　strong　c-axis　texture　and　the　maximum　magnetic　energy　product　of　22.3　MGOe　(177　kJ/　m3).　The　hot-deformed　Sm0.4Pr0.6Co5　magnets　showed　the　microstructure　with　coexisting　RECo5　main　phase　grains　and　dispersible　RE-rich　phase　nanoprecipitates.　As　the　temperature　increased,　the　crystallographic　orientation,　grain　size　and　magnetic　domain　size　were　increased.　The　coercivity　mechanism　of　hot-deformed　Sm0.4Pr0.6Co5　magnets　was　controlled　by　nucleation,　and　the　high　deformation　temperature　led　to　a　decrease　in　the　reverse　nucleation　field　and　coercivity,　accompanied　by　a　large　reversible　magnetization　during　magnetization　reversal　and　a　large　recoil　magnetic　permeability.　This　study　provides　valuable　insights　into　optimizing　the　microstructure　and　magnetic　properties　of　nanocrystalline　SmCo5　magnets,　which　is　expected　to　promote　high　temperature　applications　of　rare　earth　permanent　magnet　materials.