The backfilled silty soil around the basement in the yellow plain area is not dense, and the extreme rain water penetrates around the basement, causing the basement to float. By reducing the permeability coefficient of the loose silty soil, the loose silty soil is prevented from penetrating. In this paper, water glass, sodium bicarbonate and styrene acrylic emulsion are used to modify the loose silty soil. The gel time, variable head penetration experiment and slurry infiltration were studied. The results show that when the ratio of each component to water in the mixed grout is 5:45 and 15:45 for water glass, 5:45 and 15:45 for styrene acrylic emulsion and 0.8~1.5:45 for sodium bicarbonate, the gel time is greater than 10 minutes, the whole gel can be coagulated to meet the requirements of grouting modification. When the ratio of sodium silicate to styrene acrylic emulsion and sodium bicarbonate to water is 15:15:1:2:45, the permeability coefficient of the silt is 1×10-8 ^cm.s^-1. Soil water content has significant influence on slurry permeation distance, so modification should be carried out in spring. The amount of water glass has a significant effect on the change of slurry penetration distance, and the distance demand can be achieved by adjusting the amount of water glass. The permeability coefficient of the modified soil gradually increased from 1×10-8 ^cm.s-1 ^{to 1×10}-4 ^cm.s^-1 close to that of the plain soil when the slurry permeated from top to bottom. According to the microscopic analysis of electron microscope, the grout can inhibit water mainly by forming a hydrogel layer on the soil surface and filling the pores between the soil particles with gel in the soil body.