There are numerous influencing factors of the risk consequences of dam break. Scientific and reasonable index system and its weight distribution is one of the key element for comprehensive evaluation of the dam-break risk. Taking into consideration of 20 factors, including hazards, exposure and vulnerability factors, the evaluation index system of the consequences of the dam break risk is constructed. Using the Statistical Cloud Model (SCM) to improve the entropy method, we establish the weight calculation model of the influencing factors of the dam break risk consequences. The results shows that the top 5 factors with the highest weight are risk population, flood intensity, alert time, risk understanding and distance from the dam. Compared to the traditional algebraic weight calculation methods, the result is basically consistent with the algebraic weight distribution, and increases the range by 2.03 times, supporting a more scientific basis for recognizing and evaluating the dam break risk consequences.