ABSTRACT Based on the characteristics that the cloud model can deal with the uncertainty and fuzziness in the calculation results well, the scale criterion of the analytic hierarchy process (AHP) is improved, the scale criterion of the cloud model based on the index scale is proposed, and the expert scoring constraint mechanism is introduced. Taking the downstream area of Zipingpu Dam as the research area, the AHP based on the improved cloud model is used to carry out the uncertainty analysis of the impact factors for the comprehensive assessment of the dam failure consequences. The final calculation results are represented by the three digital characteristic values of the cloud model, and the weight of each impact factor in the assessment index system is analyzed. This method has provided a new way for a comprehensive assessment of dam failure consequences.