Magnetic Ascorbic Acid-coated Fe₃O₄ Nanoparticles were successfully synthesized via a hydrothermal route. The resulting products were characterized by Transmission electron microscope, Fourier transform infrared spectra and X-ray diffraction. Various factors affecting the uptake behavior were discussed, including the pH, adsorption time, adsorbent dosage and initial concentration on the absorption of Cr (VI). Moreover, the thermodynamics and dynamics of the hexavalent chromium ion adsorption were also studied. The results showed that a maximum adsorption capacity was 39.12 mg/g for Cr (VI) at pH 1.50 and the absorption can be up to 85%. The adsorption performance of magnetic nanoparticles in line with both the Langmuir adsorption of Cr (VI) thermodynamic model and HO secondary dynamic adsorption one.