Yichang-Wanzhou Railway is the most complicated project in southwest of China. The conditions of construction are the toughest, the most dangerous in the history of China railways. As to reduce the chance of gushing water and projecting mud soil, the theory of risk management have been introduced and applied in practice for first time. At the same time, the conception of high risks has been put forward and the systemic measures for risk management have been established. Some of the measures are studied and applied for the first time in railway projects including supervisor of geometry survey, advance geometric forecast, safe management at different grades, water monitoring and alarm system. All of these can provide experiences for other karst tunnel's risk management.