Grouting material for reinforcing silty cohesive soil karst cave and preparation method of grouting material

The invention belongs to the technical field of grouting materials, and particularly relates to a grouting material for reinforcing a silty cohesive soil karst cave and a preparation method of the grouting material, and the grouting material is prepared from the following raw materials in parts by weight: 100-200 parts of clay, 200-400 parts of cement, 80-100 parts of granite powder, 10-20 parts of sodium metaaluminate, 10-20 parts of polyvinyl alcohol, 10-15 parts of polysaccharide and 100-200 parts of water. The cement is used, the mine waste clay and the granite powder are further added, part of the cement is replaced, the cost can be reduced, the viscosity of a system can be improved through the clay, and the curing time can be shortened; polysaccharide and polyvinyl alcohol are also added and can be self-assembled into gel after being mixed, so that the integrity of the material is improved, and when the material is damaged, negative and positive ions and hydrogen bonds in the damaged part of the materia