The　hard-magnetic　SmCo5-based　materials　with　high　coercivity　have　an　enormous　range　of　high-value-added　technological　applications.　We　reported　the　novel　synthesis　of　SmCo5　particles　with　desired　particle　size　by　a　microwave-assisted　combustion　process.　The　process　consists　of　a　combination　of　Sm-Co　oxide　precursor　preparation　by　microwave-assisted　combustion,　and　the　following　calcium　hydride　reduction-diffusion.　The　microwave-assisted　combustion　offers　a　time　and　energy-saving,　and　environmentally-friendly　methodology　to　form　the　homogenous　Sm-Co　oxide　precursor　nanoparticles.　This　high-quality　Sm-Co　oxide　precursor　paves　the　way　for　achieving　high　coercivity　in　SmCo5　magnetic　materials.　A　high　coercivity　up　to　39.2　kOe　was　achieved　in　the　aligned　SmCo5　particles.　These　SmCo5　magnetic　particles　show　promising　prospects　for　high-performance　permanent　magnet　applications　and　can　be　utilized　for　the　development　of　exchange-coupled　nanocomposite　magnets　with　high　energy　density.　This　work　also　provides　instructive　information　for　designing　and　synthesizing　rare-earth-based　magnetic　materials.