Because of the frequent encountering of serious geological hazards during construction of rivercrossing tunnels, preconstruction geology forecast is rather essential. Taking Liuyang River Crossing Tunnel on WuhanGuangzhou passengerdedicated railway as an example, the authors present the application of the integrated advance geology forecast system in Liuyang River Crossing Tunnel in detail. Then, in order to summarize the advantages and disadvantages of these two methods from practice, they mainly analyze the effects of TSP and infrared water detectors. Subsequently, they put forward solutions to improve the effect of the integrated advance geology forecast system.