The metastable crystallization phase of Fe-based alloys remains a popular topic in alloy research. The α-Mn type metastable phase was observed during the crystallization of Fe80Zr10B10 amorphous alloy. Fe80Zr10B10 amorphous alloy ribbons prepared by melt spinning were annealed at different annealing temperatures and times. Different annealing temperatures indicated that there were large differences in the crystallization phase constitution. Different annealing times indicated that the α-Mn type metastable phase preferentially nucleated relative to the α-Fe phase. A long annealing time resulted in the precipitation of α-Fe and ZrB phases. As the annealing time increased, saturation magnetization (Ms) of the alloy increased gradually (from 75.48 to 122.74 A m 2 /kg), and coercivity (Hc) of the alloy increased dramatically (from 0.17 to 15.16 kA/m).