Abstract: Karst geology has a serious impact on the structural design，construction and operation of construction projects，and conventional geological exploration methods have high cost，low efficiency and narrow coverage，which are difficult to adapt to the current high requirements and strict standards. Based on a tunnel project，the cross-hole elastic wave CT technology was used to carry out karst geological exploration on the site. The cross-hole elastic wave CT test and borehole data were jointly analyzed，and the more accurate geological interpretation results were obtained. The test shows that the cross-hole elastic wave CT technology has high accuracy in karst exploration and is recommended for promotion.

Key words: cross-hole elastic wave CT technology, karst geologic, geological prospecting