Abstract: Through the investigating the soft stratum,the structural plane distributing and style,petrous and terrene mechanical character,shearing resistance,weathering intensity and the relation with free face in the reservoir bank,the article has founded out water bearing bed distribution,thickness,burying depth,groundwater type,replenishment and excretion condition,judged the stability influence from reservoir band rocky property and joints after reservoir storage water.At the same time,doped out and evaluated the type of collapse banks.In the end,the paper proved prevention and curs countermeasures and projects.