Abstract: Considering the heterogeneity and low permeability of the clay materials, the fracture grouting reinforcement characteristics of the clay are analyzed in view of the disease treatment of soft clay stratum in underground engineering. Based on Weibull distribution function theory, a heterogeneous clay formation model was constructed, and the clay was simulated by splitting grouting. Based on the results of grouting simulation, the influence of different uniformity and permeability coefficients on the grouting effect of clay splitting was analyzed. The results show that the difficulty of splitting grouting increases with the increase of the uniformity of soil mass, and the crack produced by splitting of soil mass with higher uniformity is relatively single and the distribution range of crack is smaller. The crack width is larger and the influence range is wider when the soil is less homogeneous. The length and growth amplitude of slurry vein expansion decrease with the increase of soil permeability coefficient. The width of slurry vein in the soil with a large permeability coefficient is larger than that in the soil with a low permeability coefficient. The length of slurry vein in the soil with a small permeability coefficient is always larger, and the farther the slurry vein is from the grouting hole, the smaller the width. The research has important guiding significance for the engineering application of fracture grouting in soft clay stratum.