Excessive fluoride ion in water is seriously harmful to people's health. In order to seek cheap and efficient adsorbent to remove excessive fluorine ion from water,the paper prepared iron and aluminum oxide adsorbent by coprecipitation-roasting method and made it be used to adsorb fluoride ion from aqueous solutions.It probed the effects of some parameters such as ratio of iron and aluminum oxide,adsorption time, initial concentration of fluoride ion, pH value on Adsorption of fluoride ion. Results showed that the maximum removal rate of fluoride ion is 92.5%, under the conditions that the ratio of iron and aluminum oxide is 1∶2, fluoride ion initial concentration is 100mg/L, adsorption time is 30 min, pH value is 6.0, solid-liquid ratio is 4 g/L.