Abstract: In order to find out the removal method of low concentration phosphorus in surface runoff after urban heavy rain, The adsorption characteristics of fly ash, activated carbon, zeolite and other materials on low-concentration phosphorus were investigated, and the surface of the bank slope protection brick was modified by the selected adsorption materials to make non-sintered ecological brick materials. The effects of adsorption amount, phosphate concentration and reaction time on the adsorption efficiency of phosphate bricks were studied systematically. The absorption capacity of alfalfa on the surface of eco-bricks was also investigated. The results showed that:(1) Among 3 adsorbent materials, fly ash has the best adsorption effect on phosphate. In 3 hours, the removal rate of phosphate is 54% higher than that of zeolite and 67% higher than that of activated carbon. (2) When the ecological brick surface was loaded with 36 mg/cm² fly ash, the eco-brick material showed the best phosphate adsorption performance, and the phosphate removal rate was increased by 14% compared with the ecological brick material without the fly ash. (3) The adsorption of phosphate by ecological brick material accords with the Freundlich adsorption isotherm equation and the intraparticle diffusion equation. The adsorption mechanism of phosphate is the physical adsorption dominated by intraparticle diffusion. (4) Under the condition of phosphorus deficiency stress, alfalfa secreted citric acid to dissolve the calcium phosphate crystal on the surface of ecological brick, and then absorbed it into the plant. The desorption ratio of phosphorus on the surface of ecological brick was 38.40%±0.37% in 15 d. Studies have shown that fly ash-modified non-sintered ecological brick materials have a good adsorption effect on phosphate, and the adsorbed phosphate can be absorbed by plants to achieve natural regeneration of ecological brick materials.