Abstract: Absrtact: In order to solve the problems of ecological fragility and scarcity of water resources in coal-rich areas of Western China, rational utilization and protection of water resources, artificial dam body is connected with safe coal pillar dam body, and mine water is purified, stored and utilized through closed goaf, thus forming a mine underground reservoir. The safety of artificial dam body is the precondition of normal operation of groundwater reservoir. The safety evaluation of dam body includes many indexes, criteria and levels. In order to objectively and accurately evaluate the safety of dam body, the weights of factors at different levels are calculated by analytic hierarchy process (AHP). The comparative judgment matrix is established and the consistency test is satisfied. The evaluation set is established to be fuzzy. Based on the theory and expert questionnaire, the membership degree of the evaluation factors is determined and the evaluation matrix is obtained, and the safety of the artificial dam body is evaluated comprehensively. Finally, the artificial dam body of Daliuta underground reservoir in Shendong mining area is evaluated by multi-level fuzzy comprehensive evaluation. The results show that the dam body is in a safe state.