Considering the requirement of environment and ecosystem, permeable pavement gradually became a hot issue recently. However, the conventional permeable pavement only allowed the surface layer for drainage, while the permeable subgrade was less mentioned. In addition, the acceleration of urbanization process was accompanied by a large number of municipal solid waste (MSW) production. Among the treatment method towards MSW, incineration was widely used around the world, and resulted in a huge amount of municipal solid waste incineration (MSWI) bottom ash. Thus, the MSWI bottom ash was proposed to act as permeable subgrade material in this paper, since its low cost and eco-environmental nature. According to the test and calculated results, MSWI bottom ash presented excellent adsorption capacity towards methylene blue, around 5.44 mg/g, which was regarded as one typical organic pollutant. Through observing its microstructure and calculation based on isothermal adsorption equilibrium data, the adsorption process is mainly occurred in the form of physical adsorption. Considering above adsorption parameters, the contaminant migration and transport inside the subgrade towards surrounding environment was evaluated according to solute transport model, including influence factors like hydraulic behavior, adsorption, diffusion etc. The calculation results indicated that the adsorption capacity of MSWI bottom ash effectively retarded the diffusion of contaminant.