Nanoscale CuFe2O4 was anchored on the surface of multiwalled carbon nanotubes (MWCNTs) as a magnetic heterogeneous catalyst to achieve efficient and sustainable activation of peroxymonosulfate and degradation of levofloxacin through the synergistic effect of the above materials. The catalyst properties were characterized by a series of detection techniques. It was found that the mass ratio of MWCNTs-CuFe2O4, operational parameters and common interfering substances influenced the levofloxacin removal efficiency to a certain extent. This study sheds light on the ultraefficient removal of levofloxacin with the MWCNTs-CuFe2O4(1:3)/peroxymonosulfate system, which has advantages over other reaction systems. More importantly, we propose two pathways of peroxymonosulfate activation, including free radicals and nonfree radicals, in which superoxide radicals and signal oxygen are the main active species. In addition, we observed that the MWCNT surface groups contributed to the peroxymonosulfate activation processes with the generation of extra reactive species. The Fe3+/Fe2+ and Cu2+/Cu+ redox cycles are conducive to the continuous generation of active species. The results of the catalyst recycling test, metal ion leaching test and mineralization test suggested that the fabricated catalyst had excellent catalytic stability, sustainability and mineralization ability. In addition, twenty-one intermediates were detected using liquid chromatography-mass spectrometry, and three possible degradation pathways were further proposed. MWCNTs-CuFe2O4 makes up for the shortcomings of transition metals and single carbon materials in activating peroxymonosulfate to treat wastewater and have significant potential to improve the separation and catalytic capacity of the catalyst. This study provides new ideas for the design of high-performance multiphase catalysts for applications in catalytic oxidation and proposes new insights into the mechanistic investigation.