In response to the problems of large deformation, fracture closure and poor permeability of the surrounding rocks in the weak rock roadways of the 1 000 m or deeper coal mines, it is required that the grouting material has good injectability, fast solidification speed, high early strength, and strong bonding performance. A new method of synergistic preparation of inorganic grouting materials was designed using “component optimization + ultra-fine + nano-reinforcement + organic modification”. An inorganic grouting material with an optimum composition ratio of 50∶40∶10 for the ternary cementing system of calcium sulphate aluminate, gypsum and lime was developed. After ultra grinding, the compressive strength of the concretion increased by 163.0% within 4 hours, achieving initial early strength and rapid solidification. A nano-lithium-aluminium hydrotalcite reinforcement material with synergistic effects of nano-nucleation-induced crystallization and lithium ion promotion was developed, resulting in a 183.7% increase in the 2 h strength of the ultra grinding grouting material. The organic modifier with directional coupling effect at the coal-rock interface was synthesized, which formed a bridge through bonding with the grout and coal interface, significantly improving the bonding between the slurry concretion and the coal rock interface. The synergistically prodeuced inorganic-organic composite grouting reinforcement materials has small particle size (D95
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