Abstract: Firstly, the basic information and physiognomy style of Karst Physiognomy of QiYueshan tunnel are introduced in this paper. There are multilayers in the surface karst cave of this area which have different scales and shapes. Secondly, it describes the characteristic of karst cave system of Deshengchang trough valley,including the development characteristics and conditions of Taiping cave and Wutongmiao cave. It also introduces the vertical zoning characteristics of karst cave system of Deshengchang trough valley including karst strongly developed strip, karst middling developed strip and karst weakly developed strip. Then the karst development rules of the area are introduced including karst development characteristics in the same direction, cranny and faultage area. At last the safety depth in given damaged area is predicted through FE method and the result is considered to be beneath 22.25m.