Abstract: The effects of fly ash, slag powder on hydration heat, volume stability and crack resistance of grouting reinforcing materials were studied. The results show that the hydration heat and its release rate were decreased and vertical expansion was postponed when fly ash and slag powder were added to grouting material. The early vertical expansion rate of the grouting material with fly ash was increased, and the shrinkage rate of the long-term dry shrinkage was greatly reduced. Field tests show that after adding fly ash, grouting reinforcement material hydration exothermic peak and the maximum temperature difference decreased significantly, the early strength also significantly decreased. After optimization, the crack-resistance performance of the grouting reinforce material has been significantly improved.