Due to passing through complex soil and rock stratum, the tunnel work of Taipei MRT Xinyi line between Elephant Mountain Station (R05) and the tail track section (R04) is a highly challenging job. Therefore, the construction team paid great attention to the planning and management of the tunnel work to deal with the highly difficult geology. The methods used to eliminate barriers during the construction process and the precise tunneling management can be used as a reference for construction in similar stratum.