The revealed karst, karst features and treatment measures are described in detail, and different types of karst-specific countermeasures are put up. At the same time, it is stressed that in the encounter of large-scale high-pressure water-rich cavity filling, macro-scopical analysis and understanding of the geological background governs in determining the treatment schedule. The by-pass schedule pertaining to large-scale karst cavities during construction is put up, and relatively construction organization is modified to ensure the project term target. All these can provide reference for the construction of the long karst tunnels.