Bentonite-supported magnetite particles (MagBt-p) were prepared by co-precipitation. The adsorption capacity of Bentonite-supported magnetic particles on waste water containing OrangeⅡ was tested. Some influence factor such as the dose, the initial concentration of OrangeⅡ, the pH, the contact time and the presence of surfactant were studied. Results showed that cation surfactant (CTAB) greatly enhanced the adsorption of OrangeⅡ. The maximum removal efficiency was 96.6% at 180mg/L (CTAB) and beyond this concentration there was almost no adsorption. Besides, the removal efficiency was affected by pH and contact time, the maximum removal efficiency was found at pH 2.1-3, the adsorption was rapid during the first 120 min and then equilibrium within 180min.