Abstract: Based on the theory of particle flow, the domain of flow is defined by using the Fish language implemented in PFC, and the formulas for flow and pressure are put forward respectively. Furthermore, the contact-bond model is introduced due to the complicated properties of low permeability soil to establish PFC model, which can reflect Fluid-solid coupling between particle flow and flow domain. Based on the above study, the process of fracture grouting in soil is simulated from the micro-viewpoint under coupling environment. In addition, the emergence and development of crack and grouting pressure in soil is analyzed under different grouting pressures and soil properties. The research results show that pressure plays a key role in consolidating the soil by fracture grouting, but in fact it should be kept in a reasonable value in order to form grouting slurry net entirely. Under certain grouting pressure, it indicates that the macroscopic response of grouting in soil is related to microscopic parameters of soil, such as particle size ratio, friction, and bond properties. The conclusion of numerical simulation agrees well with the field tests and grouting theory. The meaning of this research lies in the fact that PFC can make the microcosmic research of fracture grouting in soil possible and lead to a further understanding of grouting mechanism in soil. The research will be helpful to the application of PFC to the theoretical studies on grouting in the future.