Reservoir dam structure guarantees the safety of the public's lives and property and has always been attention worldwide. However, a systematic discussion still needs to be on assessing the safety risk of reservoir dam structure (RDS). This study develops an overall framework for the safety risk assessment of RDS and establishes an evaluation index system. A risk assessment model is constructed based on the cloud and D-S evidence theories. The empirical research results of the XY reservoir project verify the model's reliability. This study provides theoretical support and solutions for managers to make scientific decisions and promotes the development of industry standardization.