Soft plastic red clay covers the limestone. The change of surrounding environment easily leads to the connection and flow between red clay and karst cave, which could result in karst geological disasters such as ground subsidence, and brings serious safety risks to the construction and operation of metro tunnels as well as the surrounding environment. Taking the Dahualing Station to Jiangxiaketing Station of Zhifang Line (Line 27) of Wuhan Metro as an example, the distribution and development characteristics of red clay and karst are summarized in combination with special karst investigation. On this basis, the treatment measures of red clay and karst are put forward. Practice proves that these measures ensure the construction safety and operation safety of metro shield tunnel, and achieve the expected results, which could be reference in similar projects.