Sm2Fe17N3　compounds　have　emerged　as　promising　candidates　for　a　new　generation　of　cost-effective　permanent　magnet　materials.　In　this　work,　the　Sm2Fe17N3　particles　were　synthesized　through　a　series　of　steps　involving　mechanochemical　and　thermally　activated　reduction　of　metal　oxides　with　calcium,　followed　by　nitridation.　Our　results　demonstrate　that　the　mechanochemical　milling　of　precursors　significantly　reduces　the　temperature　required　for　the　subsequent　reduction-diffusion　reaction.　This　enables　the　synthesis　of　Sm2Fe17N3　hard　magnetic　particles　at　a　temperature　below　the　melting　point　of　calcium,　which　is　250　degrees　C　lower　than　those　required　for　conventional　reduction-diffusion　processes.　This　reduction　in　temperature　led　to　a　decrease　in　the　Sm2Fe17N3　particle　size.　Specifically,　at　a　reduction-diffusion　temperature　of　800　degrees　C,　ultrafine　Sm2Fe17N3　particles　with　an　average　diameter　of　0.30　mu　m,　slightly　smaller　than　the　theoretically　critical　single-domain　diameter,　were　obtained.　The　kinetics　of　the　mechanochemical　reactions　occurring　during　ball　milling　have　been　extensively　investigated.　By　fitting　the　proposed　theoretical　model　with　the　experimental　data,　the　kinetic　parameters　and　quantitative　expressions　were　determined.　This　work　provides　an　in-depth　understanding　of　environmentally　friendly　and　low-cost　mechanochemical　processes,　offering　instructive　information　for　the　development　of　highperformance　Sm2Fe17N3　permanent　magnetic　materials.