Water inrush does serious harm to underground engineering. Practice has proved that grouting is an effective technical means to manage water inrush. In recent years

the research on grouting theory for fractured rock mass has become hot

but the fractured hydrodynamic grouting theory develops slowly which was not enough to guide the grouting engineering practice effectively. On the basis of U-shaped diffusion law of horizontal fracture dynamic grouting

the small scale model test system for fracture dynamic grouting with variable inclination is developed. The inclination influence mechanism for grouting diffusion in hydrodynamic conditions is studied by carrying out multi-group indoor model tests and simulating fracture dynamic grouting diffusion process with certain inclination by COMSOL software. The research shows that it meet the U-shaped diffusion law when the fracture is horizontal

and it presents comet-shaped diffusion law under the influence of water head difference and gravity when the fracture existed inclination. Grouting rate and inclination presented parabola-shaped relationship curves under same diffusion effect

and increasing grouting rate can keep the concentration gradient advantage of grouting hole compared with around area. Some suggestions for reference to guide engineering practice are proposed on basis of research results. The conclusions are important complements for the present fractured hydrodynamic grouting theory

and play a positive role to guide grouting engineering practice.