[en] This paper aims at the study on the antibacterial activity of nCu-MWCNTs combined with H₂O₂ against gram-negative bacteria Escherichia coli (E. coli). The antibacterial ability of nCu-MWCNTs/H₂O₂ was evaluated by traditional surface plating method, fluorescence and SEM imaging, and the effects of variables (contacting time, dose of nCu-MWCNTs and dose of H₂O₂) were investigated. By comparing with other five processes including H₂O₂, MWCNTs, nCu-MWCNTs, MWCNTs/H₂O₂ and nCu/H₂O₂, nCu-MWCNTs and H₂O₂ was proved to have superlative antimicrobial effectiveness against E. coli. The role of nano-Cu, MWCNTs and H₂O₂ in the antimicrobial activity of nCu-MWCNTs/H₂O₂ was clarified. The release of copper ions and formation of hydroxyl radicals (·OH) both contributed the antibacterial ability of nCu-MWCNTs/H₂O₂ system. And MWCNTs as the support might be able to promote the electron transfer in nCu-MWCNTs for copper ion release. - Highlights: • The antibacterial ability of nCu-MWCNTs combined with H₂O₂ was evaluated. • nCu-MWCNTs/H₂O₂ exhibited superior antibacterial effect against E. coli. • Synergistic interaction happened between nano-Cu, MWCNTs and H₂O₂. • MWCNTs promoted the electron transfer of nano-Cu and promoted the generation of ·OH. • Copper ions and ·OH contributed the deactivation ability.