Sichuan-Tibet Highway is located in the southwest of Qinghai-Tibet Plateau.Water damage to roadbed near rivers along the highway is very serious because of the complicated characteristics of geology,geomorphology, climate and hydrology. Based on field investigations,the causes and types of water damage were discussed,and the prevention of it were put forward. Finally,the application of prevention methods of water damage was applied in the K4238+196-K4239+150 section of Sichuan-Tibet Highway.