A weight calculation model of hazard factors based on particle swarm optimization-analytic hierarchy progress（PSO-AHP） is proposed.The hierarchical structure is established through analytic hierarchy progress

including the results of dam site detection

prototype monitoring

periodic inspection and so on.In order to make sure that the consistency of judgment matrix is satisfied

particle swarm optimization and penalty function method are used to calculate the weights of judgment matrix in analytic hierarchy progress.The results are more accurate and more stable than that of genetic algorithm.Finally

the model proposed is used for operation risk analysis of a dam.The main factors affecting the operation risk are obtained

and the basis for protecting the dam safety is provided.