Abstract: Ball-milled amorphous powder and ball-milled annealed amorphous powder were obtained from Fe_73.5Si_13.5B₉Nb₃Cu₁ amorphous powder, which were treated by isothermal anneal and ball milling. Comparing the degradation rates of iron powder and the 3 kinds of amorphous powder to methyl orange solution, the degradation property of methyl orange solution by Fe-based amorphous powder (Fe_73.5Si_13.5B₉Nb₃Cu₁) was studied, and the effects of reaction temperature, initial pH value of methyl orange solution and powder dosage on methyl orange solution by Fe-based amorphous powder were also investigated. The results indicate that the Fe-based amorphous powder performs better on the degradation of methyl orange solution compared with iron powder, ball-milled amorphous powder and ball-milled annealed amorphous powder, which can degrade 10 mg/L methyl orange solution near 97% within 23 h; higher temperature and lower pH value of methyl orange solution lead to the increase of degradation efficiency of methyl orange solution. The amount of Fe-based amorphous powder has a significant influence on the degradation of methyl orange; the optimum Fe-based amorphous powder dosage is 0.30 g in this experiment, and the degradation efficiency can be reduced with the increase of the powder dosage from 0.30 g to 0.70 g.