In limestone area, groundwater runoff, soil cave, loose body and well-developed karst caves often result in ground collapse so as to influence the safety of ground building. Cement slurry grouting in limestone foundation is an economical, reasonable and effective method to prevent ground collapse. In order to get various kinds of information, such as the distance of cement slurry grouting, and the conditions as to whether soil cave, loose body and karst cave are filled with cement slurry and whether grouting is dense and uniform, researchers can use borehole electromagnetic wave to carry out cross-hole inspection for grouting quality of cement slurry.