Grouting materials have significant applications in mining engineering, but their poor durability in deep and highly erosive environments severely restricts the long-term safe operation of mines. Modified grouting materials were prepared by replacing a portion of the cement with rice husk ash and slag. Using compressive strength, the strength erosion coefficient, and the mass loss rate as evaluation criteria, quantified assessments were conducted to evaluate the impact of different erosion environments on the durability of modified grouting materials in karst regions. Combining scanning electron microscopy and X-ray diffraction analysis, it revealed the erosion-resistant mechanism of the modified grouting material at the microscopic level. The results show that the rice husk ash-slag-cement grouting material exhibited the highest resistance to chloride-sulfate erosion, carbonate erosion and water leaching corrosion, with strength loss rates of 13.61%, 14.42%, and 4.79%, respectively, and mass loss rates of 3.30%, 2.38%, and 1.95%, respectively. It is more resistant to environmental erosion than pure cement grouting materials. At the microscopic level, it is observed that rice husk ash and slag form dense hydration products through hydration reactions, which can inhibit the degradation of the original hydration products caused by various corrosive environments. At the same time, the amorphous SiO₂ in rice husk ash reacts with Ca(OH)₂ through a pozzolanic reaction, and the secondary hydration of the slag generates more C-S-H gel, significantly enhancing the erosion resistance of the modified grouting material to chloride-sulfate, carbonate and water. The cost of grouting materials made from rice husk ash-slag-cement is 21% lower than that of pure cement, and they can extend the maintenance cycle of the project by approximately 51.41%.