A new magnetic mesoporous As(III) adsorbent of Fe₃O₄@SiO₂@Ce-ZrO₂ was prepared by solvothermal and sol-gel method. The core-shell adsorbent presented a high specific surface area (168.2 m²/g) and fast magnetic separation performance (5.37 A·m²/kg). Compared with Fe₃O₄@SiO₂@ZrO₂, the Ce-doped sample exhibited 12%-23% increase in As(III) uptake over pH 3-11, which was mainly attributed to the formation of bimetal M—O—As complexes. The coexisted and weakened As(III) adsorption, Ca²⁺ worked oppositely, but the impact of Cl^- and was negligible. The As(III) maximum adsorption capacity was 24.52 mg/g at 313 K with an initial As(III) concentration of 5 mg/L at pH 7, and its kinetics was well fitted by the pseudo-second-order model. Moreover, the adsorbent exhibited remarkable recyclability. It is suggested that Fe₃O₄@SiO₂@Ce-ZrO₂ is a promising adsorbent for the advanced treatment of As(III) contaminated wastewater.