Abstract: Water seepage and leakage occurs in most of the inclined shaft of coal mines in the west of China in the water-rich loose layer section, and sometimes there is even the risk of gushing water and collapsing sand, which affects the safe production of coal mines. In order to scientifically guide the water prevention and control work of inclined shaft over dynamic water sand layer, taking curtain grouting of main and auxiliary inclined shaft over dynamic water sand layer in Caojiatan Coal Mine as the background of the project, the curtain grouting diffusion plugging model of dynamic water sand layer is established with the help of finite element numerical simulation software, the mechanism of curtain grouting diffusion plugging of over dynamic water sand layer in inclined shaft of the mine is investigated, the curtain grouting parameters and process of dynamic water sand layer are optimized by combining with the specific management area, and the effect of the field effect is tested. The research results show that with the increase of dynamic water flow rate and grouting pressure, the spreading characteristics of slurry in the direction of water flow are obvious; when the grouting pressure is 0.5 MPa and the dynamic water flow rate is 0.3 m/s, the radius of slurry spreading in the direction of water flow is increased to 1.83 m; with the increase of the spacing between the inner wall of curtain and the outer wall of the wellbore, the damage range of the deformation of the surrounding rock of the wellbore is far away from the outer wall of the wellbore gradually and the spacing of the treatment area should be set at a distance of not less than 12.5 m. After the optimization of grouting parameters and process, the water inflow in the treatment section of the main and auxiliary inclined shafts is attenuated by 85.5% and 82.7% respectively, and the treatment effect is remarkable. The research results help to solve the water seepage and leakage problem of the inclined shaft in the dynamic water sand layer, ensure the safe operation of the inclined shaft and protect the underground water resources of the mine.