The paper aims at introducing a renovated hazard assessment model for the consequences caused by the dam failure based on principal component analysis. Since such dam failure hazard assessment involves a lot of influence factor characteristics of correlation, it is of essential necessity to evade subjective factors as much as possible. In this way，the principal component analysis is expected to make the complexity related factors visualized. As a case study, the paper tried using this model to evaluate the consequences of dam hazard of five reservoirs in Jiangxi Province. With standardized data, and by calculating the correlation coefficient matrix, the main compositions and weights based on the contribution of an integrated factor can be determined, the principal component values and comprehensive scores gotten, and in combination with the risk evaluation criteria, the consequences of the dam level and sequence finalized. The results of our analysis show that the consequences of the failure of the abovementioned five reservoirs are all serious which belong to the special events of the dambreaks. Thus the application of the model shows that principal component analysis can reflect the dam hazard level more objectively with its application being simple and ratiocination close. Therefore, it can be considered as a promising method with great potential for future development.