The　effect　of　magnetic　field　annealing　methods　on　soft　magnetic　properties　for　nanocrystalline　(Fe0.5Co0.5)(73.5)Si13.5B9Nb3Cu1　alloy　was　investigated.　In　contrast　to　nonmagnetic　field　annealing,　the　magnetic　field　annealing　can　obviously　reduce　saturation　magnetostriction　lambda(s)　and　increase　effective　magnetic　anisotropy　＜　K　＞.　Furthermore,　the　initial　permeability　mu(i)　of　experimental　samples　can　be　enhanced　significantly　after　magnetic　field　annealing.　Different　magnetic　field　annealing　methods　produced　varying　degrees　of　impact　on　the　mu(i)　of　samples,　which　is　ascribed　to　the　difference　of　obtained　lambda(s)　and　＜　K　＞.　In　three　magnetic　field　annealing　methods,　the　magnetic　field　nanocrystallization　can　manifest　more　effective　magnetic　field　effect　compared　with　other　two　magnetic　field　annealing　methods　and　achieve　more　superior　magnetic　softness,　the　reason　of　which　was　also　analyzed.　(C)　2015　AIP　Publishing　LLC.