The invention discloses a geopolymer grouting material and a preparation method thereof. An inorganic silicate composite material is prepared from 71-91 parts of mineral waste residues, 66-70 parts of coal ashes, 16-28 parts of alkali-activator and 0.5-1.6 parts of retarder; and then, the inorganic silicate composite material is mixed with water according to a proportion of 0.30-0.38 to prepare the geopolymer grouting material. The geopolymer grouting material disclosed by the invention has characteristics of being good in liquidity, high in early strength, free of shrinkage, good in durability, adjustable in setting time and strength. Compared with the conventional geopolymer polymer material, the material is a composite material formed by mixing various powder materials, and can be applied by adding water and stirring on the spot; the geopolymer grouting material is simple in preparation process, low in cost, convenient to operate, capable of being widely applied to cement concrete pavement slab bottom grouting, cement concrete pavement crack repairing, foundation bolt anchoring, equipment installing, pres-stressed bridge crack pouring, engineering repairing, reinforcing, and the like.