The sorbent was obtained by modifying the Mg-Al hydroxide using sodium stearate. Phosphorus wastewater was treated by modified hydroxide. Single factor and  orthogonal experiment show that the effect order of the four factors on the removal rate of phosphorus is as follows: adsorbent dosage > adsorption time > wastewater pH> adsorption temperature. The most suitable conditions are adsorbent dosage is 0.7 g, adsorption time is 80 min，wastewater pH is 3.5 and adsorption temperatures is about 25℃ and under the optimal conditions， wastewater the removal rate of phosphorus is 92.8%.