Taking the construction of Yesanguan tunnel and Dazhiping tunnel on Yi-Wan railway as case histories, the paper expatiates on the comprehensive geology prediction program adopted for the karst tunnels with high risks. On basis of the case histories, the paper presents the geology prediction methods and the data processing methods actually adopted during the tunnel construction. By means of the geology prediction technology presented, the largescale faults are successfully predicted and importance guidance is provided for the tunnel construction.