[Objective] The environmental risk of dangerous goods transportation in sensitive water environment section of the Qinghai-Tibet expressway was analyzed in order to make the corresponding prevention and the emergency countermeasures.[Methods] Based on the identification of the water environment sensitive section along Qinghai-Tibet expressway, the environment risk of the dangerous goods transportation was predicted by probability estimation method.[Results] The length of the water environment sensitive section was 477.48 km, accounting for 42.77% of the total length of the Qinghai-Tibet expressway. Among them, the high sensitive section was 89.52 km, the medium sensitive section was 221.49 km and the low sensitive section was 166.47 km. The traffic accident probability of dangerous goods transportation vehicles on Qinghai-Tibet expressway in the forecast year was low, with the average probability of 0.162 5~1.176 0 t/a. The risk of environmental pollution in dangerous goods transportation accidents could be ranked as:medium sensitive section > high sensitive section > general section > low sensitive section. By improving the road pollution prevention and the emergency measures as well as the management and monitoring of the dangerous goods transport vehicles, the environmental pollution risk caused by the dangerous goods transport accidents could be effectively reduced.[Conclusion] The water environment sensitive section of Qinghai-Tibet expressway accounts for a major part of the studied road. Pollution prevention measures and emergency measures can effectively reduce the environmental risks of dangerous goods transportation on Qinghai-Tibet expressway.