Abstract: Nine kinds of activated red mud particles with different mass ratios were formed, with the red mud as main raw material, fly ash as the excitation agent, bentonite as binder and sodium bicarbonate as foaming agent. The capacity of phosphorus adsorption in solution was compared throughL₉(3⁴) orthogonal test with nine new types of activated red mud particle materials. Using the phosphorus adsorption rate after 8 hours of adsorption time as the evaluation standards, with the initial concentration of phosphorus 6.0 mg/L and pH 8.0, the adsorption capacity of phosphorus of No.8 red mud particles was 1.0 mg/g with the phosphorus removal rate of about 83.7%, while the adsorption capacity of phosphorus of No.3 red mud particles was merely 0.1 mg/g with the phosphorus removal rate of about 7.2%. From characterization and comparison by infrared spectroscopy and XRD(X-diffraction) on the physicochemical properties of two calcined red mud particles adsorbed materials, it was shown that the calcined red mud particles surface had (-OH) substance functional group which could exchange ligand with phosphate in the solution and thus achieved adsorption. The red mud content is a key factor affecting the adsorption effect.From characterization and comparison by infrared spectroscopy and XRD (X- diffraction) on the physicochemical properties of two roasting red mud particles adsorbed material, we could see that the calcined red mud particles surface had (-OH) substance functional group, and it could exchanged ligand with phosphate in solution and achieved adsorbed.