Fe–Si–B amorphous alloy ribbons (Fe–Si–BAR) are widely investigated recently due to its high efficiency in remediation of wastewater containing azo dyes and other organic pollutants. In this paper, the effects of Fe–Si–BAR on the remediation of water containing high levels of Cu2+ ions were discussed. Results show that the reaction mechanism of Fe–Si–BAR with Cu2+ ions solution is the same as iron powders (FeCP). But the reaction efficiency of Fe–Si–BAR is about 167 and 34 times than that of FeCP for the Cu2+ ions solution of 100 mg/L and 500 mg/L, respectively. Furthermore, the apparent reaction activation energy is calculated to be 18.7 and 19.4 kJ/mol for Fe–Si–BAR and FeCP, indicating that both the reactions of Fe–Si–BAR and FeCP are diffusion-controlled process. Microstructure investigations shown that loose product layer on the surface of the Fe–Si–BAR contribute to the high efficiency of Fe–Si–BAR in remediation of heavy metal-polluted water. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.