To meet the durability requirements of synchronous grouting materials for tunnels under complex geological conditions, ternary geopolymer grouting materials were prepared using materials such as fly ash, slag and metakaolin, and their durability performance was studied. On the basis of exploring the physicochemical properties of raw materials, a durability test was designed using Box Behnken in response surface methodology. The test results were analyzed for significance, variance and three-dimensional response surface methodology. XRD, SEM and EDS were used to analyze the microstructure and hydration products of the polymer stone body. The results show that fly ash, metakaolin and slag can form a complementary effect, and their interaction has a significant impact on the erosion coefficient of grouting materials, which can effectively enhance their resistance to sulfate ion erosion. Prediction determination coefficient R2pred is 0.932 8, the relative error of the experiment is 0.71%, and the model accuracy is high. Through optimization, the optimal mix ratio parameters are cement 45.183% (mass fraction, the same below), fly ash 20%, metakaolin 20% and slag 14.817%. The hydration products of geopolymer grouting materials are mainly calcite, C-A-S-H and N-A-S-H gel, which are closely connected and grow in a staggered manner, forming a dense three-dimensional spatial network structure support system, effectively enhancing the durability of the materials. The research results can provide reference for the subsequent research and production application of durability performance of ternary geopolymer grouting materials.