In our study, we used the multi-channel transient Rayleigh wave method and geological prospecting data, to detect the karst fractures in the rock masses bearing cliffside inscriptions in the Seven Star Cave of Guilin. The results reveal the scale and distribution of karst fractures that cause the cliffside inscriptions to be eroded due to water in the karst fractures. Application of the multi-channel transient Rayleigh wave method to karst fracture exploration provides not only a scientific basis for protection of cultural relics involving wall carving, but also experience and references for other relevant engineering projects.