In response to the major water hazard of water and sand outburst in the loose strata of the thin bedrock area of coal seam roof, this paper analyzes the four necessary conditions for water and sand outburst, namely water and sand sources, channels, power sources and accommodation space. The "driving water and solidifying sand" grouting control technology was proposed. This technology changes the hydrodynamic conditions of the loose strata through high-pressure grouting, forming a "root skeleton" network structure, displacing the water in the loose sand layer and enhancing its stability. On this basis, the selection and parameters of drilling types under different hydrogeological conditions were proposed, and four grouting modes, including the flat push type and the central flower type, as well as their parameters were clarified. The engineering practice in Wugou Coal Mine shows that the maximum unit water inflow of the four aquifers after grouting is 0.000474 L/s.m, and the pressure of the inspection holes increases by 15.3% to 57%. The results of the grouting return water, grouting diffusion distance, and core drilling samples verify the formation of the grouting diffusion network, effectively reducing the risk of water and sand outburst. This technology provides a systematic solution for the prevention and control of water hazards in the loose strata of the thin bedrock area of coal seam roof and has significant engineering application value.