Abstract: Aggregate betting is over under high-velocity and dynamic water conditions, and the timing of the start of grouting has always been a difficult problem for the on-site staff. The determination of the initial deposition position of the grout under different dynamic water flow rates is to design the aggregate betting scheme and inspect the grouting seal. The key to blocking effect. In this paper, a theoretical model of slurry sedimentation and migration is established by considering the interaction between discrete particles and moving water; a dynamic water grouting test is carried out based on a self-designed laboratory test system, and the initial diffusion and transport form of the slurry in the pipeline is discussed. The relationship between the initial deposition position of the slurry and the flow rate of water, the water-cement ratio and the inner diameter of the pipeline is discussed, and the laboratory test results are compared with the theoretical results. The research results show that: the initial deposition position of the slurry is positively correlated with the dynamic water flow rate, water-cement ratio and the inner diameter of the pipeline; the impact of the dynamic water flow rate and the inner diameter of the pipeline on the initial deposition position of the slurry is greater than that of the water-cement ratio; experimental and theoretical model calculation results Basically the same.