According to the geological disaster investigation on Ba-river basin of Sichuan Province, there are 11 collapses including 5 translational collapses, accounting for about 45% in total. Studies reveal that this kind of collapse has similar characteristics of translational landslide: sandstone in upper slope and mudstone at the bottom interlayer; slope angle nearly中国地质调查局地质调查项目“川东巴河流域地质灾害调查”（编号：1212011220171）、“大巴山区城镇地质灾害调查”（编号：121201019000150003） perpendicular; parallel slopes at trailing edge of the slope, fissures exposing to the surface and being enclosed on both sides. When heavy rain falls, rain flows into the fissures, which accelerates fissures expanding by hydrodynamic & hydrostatic pressure and splitting effect of high water head. The pushing out of upper sandstone layer on the mudstone layer results in free surface collapse. Therefore, the treatment measures should be paid more attention for such collapse, the prevention of water into fissures is very important.