Abstract: Due to lacking of knowledge of geological conditions in the survey and design stage, or requirements to improve the road line, highway tunnels can be constructed in large ancient landslide mass. For example, the Chuanzhusi tunnel is constructed in a large ancient landslide. This paper bases on the geological conditions of landslide occurrence and the tunnel. A detailed analysis is done on the system characteristics of the ancient landslide. Through investigation and by the construction of geological and mechanical methods, this paper studies the tunneling in through the ancient landslide. It turns up the geological characteristics of the problem, such as holes, rocks and collapse and deformation and failure mechanisms, and suggests remediation measures. The research result for the construction of the tunnel passing through the ancient landslide has an important significance.