A new type of strong adsorbent nanostructure Cu₃SnS₄@C has been first designed and fabricated by two-step hydrothermal synthesis. For removal of anionic dye methyl orange (MO), in striking contrast to the weak adsorption of bare C nanospheres (0.7 mg/g), the Cu₃SnS₄@C nanostructures exhibit a very strong pH-sensitive adsorption performance with a maximum adsorbability of 65.99 mg/g at pH 5.0 and a minimum value of 8.11 mg/g at pH 11.0, in initial concentration of 70 mg/L MO. The samples’ adsorption mechanism could be well explained by pseudo-second-order kinetic model. Such significantly enhanced adsorbability of Cu₃SnS₄@C could be ascribed to the synergistic adsorption effect of Cu₃SnS₄ nanoparticles at C nanospheres, which can induce holes transfer and thus lead to massive positive active sites generation on Cu₃SnS₄@C available for synergistic adsorption anion dye.