Constructed wetlands are widely used throughout the world to treat a wide variety of wastewater. Numerous researches on phosphorus removal have been reported, however, in practice, phosphorus removal efficiency through the constructed wetland is still relatively lower due to various reasons. In this paper, the phosphorus adsorption capacity of aerated concrete (a building material) was investigated by using Freundlich and Langmuir adsorption isotherm equations, and then the possibility, using aerated concrete waste residues for the treatment of effluent with relatively higher concentration phosphorus at the outfall of constructed wetland end through certain engineering measures, was explored. The results showed that aerated concrete not only had a higher phosphorus adsorption capacity (6.064mg/g), but also had a higher adsorption rate, compared with some other substrate materials commonly used for constructed wetlands. Coupled with the lightweight characteristic of aerated concrete, the imagination of the secondary purification pond was likely to be formed. If the imagination turns into a reality, it will not only effectively purify sewage emissions from the constructed wetland forever, but also realize the resource utilization of large quantities of aerated concrete waste residues resulting from the construction process.