In this paper, we prepared CuCo₂S₄/MWCNTs as a heterogeneous iron-free bimetal catalyst for the degradation of methylene blue (MB) dye by uniformly synthesizing CuCo₂S₄ nanoparticles on the surfaces of multiwalled carbon nanotubes (MWCNTs). The homogeneous nanostructure, tuned by MWCNTs, and the efficient electron transfer from CuCo₂S₄ to MWCNTs resulted in a quite decent catalytic activity, which was superior to that of pristine CuCo₂S₄ and monometal sulfides. Moreover, CuCo₂S₄/MWCNTs maintained a good catalytic performance over a broad pH range of 3 to 12, and exhibited better MB degradation rates under alkaline conditions. Meanwhile, the catalyst was reusable for up to three cycles due to the strong interaction between the nanoparticles and MWCNTs. The results demonstrate that CuCo₂S₄/MWCNTs is an improved Fenton catalyst and a promising candidate to substitute iron-based catalysts for the treatment of wastewater containing dyes.