In　this　paper,　magnetic　field　heat　treatment　was　carried　out　for　the　SmCo5/alpha-Fe　amorphous　powders　prepared　by　high-energy　ball　milling.　The　effects　of　annealing　temperature　and　magnetic　field　on　the　crystallization,　microstructure,　and　magnetic　properties　of　the　SmCo5/alpha-Fe　nanocomposite　permanent　magnets　were　studied.　The　results　show　that　the　magnetic　field　can　benefit　the　crystallization　of　SmCo5　phase　and　the　degree　of　crystallinity　of　SmCo5/alpha-Fe　alloy.　Thus,　the　remanence　and　coercivity　of　the　SmCo5/alpha-Fe　magnets　annealed　with　magnetic　field　are　significant　higher　than　those　of　the　samples　annealed　without　magnetic　field.　With　the　increase　of　annealing　temperature　in　magnetic　field　heat　treatment,　the　Sm(Co,　Fe)(5)　phase　and　FeCo　phase　are　gradually　crystallized　and　grew　up,　while　a　small　amount　of　Sm2Co17　phase　appears.　The　best　magnetic　properties　are　M-r　=　73.29　emu/g,　M-r/M-s　=　0.59,　and　H-ci　=　6.20　kOe,　when　the　annealing　temperature　is　700　degrees　C.