A new magnetic adsorbent, namely, MnFe 2 O 4 /D201, with deep-treatment ability and high selectivity adsorption for As(V) was prepared. According to isotherm adsorption and kinetics, As(V) adsorption is primarily used for chemical bonding throughout the single-layer adsorbing process. The maximum As(V) adsorption capacity of MnFe 2 O 4 /D201 can reach 35.8 mg/g at pH 3. MnFe 2 O 4 /D201 also exhibits higher selectivity adsorption against Cl - , NO 3 - , SO 4 2- , and PO 4 3- . According to the thermodynamic results, the adsorption process was spontaneous and endothermic. The adsorption capacity is maintained at 81% of the initial after ten adsorption-desorption cycles. As(V) concentrations ranging from 1 mg/L to 10 μg/L can be treated in fixed-bed column experiments. The effectual cure volume of As(V) reaches 1332 BV (26.64 L). The removal mechanism primarily comprises electrostatic attraction and complexation.