In this paper, manganese ferrite / biochar composites were synthesized by one-step hydrothermal method with biochar as carrier, and the adsorption characteristics and removal efficiency of heavy metal ions Cd2 , was studied. The composite was characterized by SEM,XRD,FT-IR and XPS, and the effect of initial pH,initial concentration on the adsorption of Cd2 on manganese ferrite/biochar composites were discussed , the experimental data were subjected to kinetic and isotherm fitting. The results show that under the experimental conditions of 25℃, the optimum pH for adsorption of Cd2 by manganese ferrite/biochar composites is 7.0. After 60 min adsorption, the adsorption equilibrium is reached, and the maximum saturated adsorption capacity was 32.74mg/g. The adsorption kinetic and adsorption isotherm are respectively conformed to the Pseudo-second-order kinetic and Langmuir isotherm models, and the monomolecular chemisorption plays a dominant role in Cd2 adsorption process. When the manganese ferrite / biochar composites was regenerated for 5 times, it still showed good regenerative adsorption properties for Cd2 .