The invention relates to iron-based soft-magnetic amorphous steel. The iron-based soft-magnetic amorphous steel is composed of FeaCbSicMndPeSfCrgAlhNiiBj and inevitable impurities, wherein by atomic percentage, a accounts for 74-80, b accounts for 0.02-0.06, c accounts for 9.10-11, d accounts for 0-0.25, e accounts for 0.1-0.2, f accounts for 0-0.05, g accounts for 0-1.6, h accounts for 0.03-0.07, i accounts for 0-1, j accounts for 11.10-13, and a+b+c+d+e+f+g+h+i+j=100. The alloy material has the high saturation flux density (i)B( / i)s (the maximum value of 1.7T), the high effective magnetic conductivity (i)mu( / i)e (the maximum value of 14401 at 1kHz), the high-frequency stability and the low coercive force (i)H( / i)c (the minimum value of 1.405A / m), the formability is good, the preparation technological conditions are loose, and the production cost is low.