Abstract: A large amount of waste slurry would be generated in slurry shield tunnelling, and it will result in high cost of handling and transportation, even more serious pollution problem. Based on the Houting-Juyuan running tunnel section of the Fuzhou metro, which was driven by a slurry shield underneath the Wulong River, it studied the feasibility to prepare the backfilling grouting material with waste slurry generated from slurry shield excavation, optimized the four factors affecting mortar performance by the orthogonal test, discussed the effect law of water-cement ratio, flyash-cement ratio, cement-sand ratio and specific gravity of slurry on backfilling grouting material. The results show: 1) water-cement ratio and specific gravity of slurry are the main factors affecting mortar consistency, fluidity and bleeding rate; 2) water-cement ratio and flyash-cement ratio are the main factors affecting setting time; 3)water-cement ratio, cement-sand ratio and specific gravity of slurry are the main factors affecting mortar density; 4)by controlling specific gravity of slurry and water-cement ratio the backfilling grouting material can be prepared with good working and strength performances.