In　the　present　work,　a　novel　way　has　been　developed　to　prepare　the　single-phase　nanocrystalline　Sm5Co2　alloy.　The　microstructure　and　phase　constitution　were　characterized,　and　it　was　showed　that　the　nanocrystalline　Sm5Co2　alloy　has　ultra-fine　and　homogenous　nanograin　structure　with　an　average　grain　size　of　about　10　nm.　Moreover,　the　magnetic　and　mechanical　properties　of　the　Sm5Co2　nanocrystalline　bulk　were　characterized　in　details,　and　both　properties　were　enhanced　as　compared　with　those　of　the　conventional　polycrystalline　counterparts.