Abstract: The reservoir disaster events often show the continuous evolution of the chain structure due to interactions among them, and the hazards and impacts caused by the reservoir disaster events are far greater and far more reaching than those caused by single ones. Meanwhile, the reservoir catastrophic chain effect and its chain risk are the key to study the situation evolution. Therefore, it is of great significance to make further researches on the chain effect and the chain risk assessment model for the reservoir catastrophe based on the chain effect of the reservoir catastrophe. In this paper, the risk-assessment model for the reservoir disaster chain is developed on edge number, average path length and connectivity, which are applied in describing network vulnerability. In engineering application, the analysis of the disaster chain network is carried out and the risk degree of each catastrophe chain is sorted, of which the analysis with evaluation results can provide technical support for reservoir disaster early warning and chain-breaking disaster reduction.