Herein, magnesium oxide (MgO) and ferroferric oxide (Fe3O4) functionalized biochar (MgO@MBC) was synthetized through one-step pyrolysis method, which was used to decontaminate lead (Pb) and phosphate in contaminated water. Characterization results exhibited that MgO and Fe3O4 particles were successfully loaded on MgO@MBC, and the magnetism of MgO@MBC was in favor of recycling materials. Experimental results showed that MgO@MBC possessed outstanding adsorption performance with 556.62/303.08 mg/g for Pb(II)/phosphate. Furthermore, MgO@MBC had excellent anti-interference performance under the coexistence of various ions, and superior reusability with over 82 % adsorption efficiency for Pb(II)/phosphate after four regeneration cycles. It demonstrated that the high-efficiency capacity of Pb(II) adsorbed on MgO@MBC was attributable to complexation, electrostatic attraction, precipitation, and pore-filling, while the efficient uptake of phosphate was due to precipitation, pore-filling, and ligand exchange. Based on the above analysis, MgO@MBC was believed to be an outstanding adsorbent for remediating Pb(II)/phosphate wastewater.