Abstract: Using the high density electrical method meter,used Schlumberger array to install to the Qinhe river main dike some contract section has carried on the electronic resistivity CT survey.In dam stave,subsidence,crack as well as cavern and so on hidden danger spot even clear reflections.The rivers and streams dam is its basin area people personal safety and property safeguard,is relates the peaceful country and safe people the important matter.Has the important value and the significance to the Qinhe river main dike's hidden danger survey.By the electronic resistivity image formation's method utilization,causes the explanation work to be more convenient and to be direct-viewing,and has the good usability,the validity and the feasibility.