In view of the poor textures and permeability of soils in South China, it is impossible to promptly drain the urban runoff rainwater that has grown with impervious pavement growth. A laboratory self-made filter column device was prepared based on a bioretention tank, the infiltration curve of the filter column device under different return periods was tested to evaluate the improvement effect of building waste materials with different particle size gradations on soil infiltration. The experimental results showed that the optimal particle sizes of building waste materials for the soil characteristics and rainfall conditions in south China is 5-9 mm, with the increase in the return period of rainfall, the effect of infiltration improvement is more obvious and the time for seepage is also significantly earlier. The LID bioretention tank module was constructed in SWMM and the model was calibrated based on the test results, the simulation provided reasonable parameters for the bio-retention tank. The research results have expanded the application of building waste materials in low-impact development measures and provided scientific reference and assessment tools for the large-scale sponge-city low-impact development measures for soil infiltration.