Due　to　its　large　magnetocrystalline　anisotropy　field　and　high　Curie　temperature,　SmCo-based　magnets　are　irreplaceable　in　high-temperature　applications.　The　hot-deformed　SmCo-based　magnets　are　especially　attractive　for　their　excellent　corrosion　resistance,　making　them　more　suitable　for　harsh　environments.　However,　it　is　still　challenging　for　hot-deformed　SmCo-based　magnets　to　obtain　high　magnetization　and　high　coercivity　simultaneously.　Therefore,　it　is　necessary　to　analyze　the　relationship　between　its　microstructure　and　magnetic　properties　and　explore　its　magnetic　hardening　mechanism　to　guide　the　further　improvement　of　magnetic　properties.　In　this　paper,　the　anisotropic　heterostructure　SmCo5　magnet　was　prepared　by　combining　large　height-reduction　and　introducing　a　nano-grained　Smrich　phase.　Strong　c-axis　texture,　(BH)(m)　of　16.1　MGOe,　and　H-ci　of　9.6　kOe　were　obtained　via　the　heterostructure　with　SmCo5　micron-grain　and　Sm-rich　nano-scale　precipitates.　The　magnetic　domain　observation　and　technical　magnetization　analysis　demonstrate　that　the　coercivity　mechanism　is　dominated　by　nucleation.　The　results　also　show　that　the　smooth　and　Sm-rich　precipitated　grain　boundary　provides　weak　pinning　effects.　It　provides　a　reference　for　the　development　of　high-performance　nanocrystalline　SmCo5　magnets.