Abstract:CADMAS-SURF method, widely used in coastal numerical wave analyses, is applied to numerical simulation of dam breaking for a tailing dam in Xinta mining site of Shanxi province for the purpose of research. The damage degrees of tailing dam breaking to downstream are analyzed. As a college science and technology innovation project, the time of mud reached to downstream after tailing dam breading is calculated, and impact of the auxiliary dam to the resident of downstream is studied. The study results provide a reference for disaster prevention and mitigation.