The excavation depth of the No.3 shaft on the Zhenhe to Jianhe Water Diverting Project in Xin’an County was large, where groundwater was extremely rich with water gushing and flooding. Slim pilot pipe grouting was taken to seal off seepage and gushing within 2 times the shaft diameter of the gushing point with a dual fluid made of cement and sodium silicate mortar. With grouting before excavation, the tunnel excavation was successfully completed, which can provide experience for the construction of similar projects.