Abstract: The Guiyang-Kunming, Xiangfan-Chongqing Yichang-Wanzhou and Chengdu-Kunming railway lines in China have suffered a lot of karst geological disaster. Combined with these obout existing engineering, the harm of karst on tunnel engineering is reflected not only in construction, in the post-operation process will also pose a threat. During the construction of tunnel engineering that karst have appeared, landslides is very vulnerable to happen, go with water gushing, burst mud and other phenomena, even collapse will appear, which cause downtime of tunnel construction and casualties and property losses. During post-operation process, the covered karst with a strong concealment and will pose a threat to traffic safety. In a word, the tunnel karst is one of the geological disasters can not be ignored. In the vast section of Guizhou area, which the high-speed railway of Shanghai-Kunming line cross, the karst developed widely. The hidden karst under the tunnels has a strong concealment and will be a threat to the safety of the train. Therefore, it is essential and important to find out the distribution of the hidden karst. This paper mainly talk about the basic principles and how it works about the seismic imaging method, combined with on tunnel, we found many karst cavities and fractured zones, and proved this method is effective and efficient in the complicated geologic condition.