Abstract: Foundation work will be influenced by the existence of solution cavities underground,which should be uncovered, and so that we can take effective measures to ensure the safety of surface buildings. Usually the occurrence of solution cavity is an irregular 3D geological body, and its development is closely related with the geologic structures and ground water as a low-resistivity substance,which may fill in the cavern result in the difference of physical property between solution cavity and adjacent rock with high-resistivity. So, based on this difference,we can prospect for solution cavities in karst terrain with the high-density resistivity method.Currently, with the 2D high-density resistivity method, the feedback of profiles on the apparent resistivity is uncertain resulted from lateral-effect; because of the inefficiency and the short depth of prospecting, 3D high-density resistivity method can't identify the characters of solution cavity clearly. So, in this paper, taking a study of solution cavity exploration in Guoxiangyu for example, basing on generally introducing high-density resistivity method, we will expatiate the application of the horizontal slice figure method in interpreting data and the effects of this method. The method is that the data from traditional 2D high-density resistivity are processed by horizontal slice figure in order to achieve the purpose of 3D interpretation.