The invention discloses a multi-level fuzzy evaluation method for a barrier lake. The method comprises the following steps: determining an evaluation index set U influencing subsequent development ofthe barrier lake; establishing a developable comment set V = {v1,v2,v3,v4} of the barrier lake; constructing a membership function equation,and establishing a fuzzy relation matrix R which is equal to[rij] n * m; determining the weight A of each grading index,and determining the weight of each grading index by adopting an improved analytic hierarchy process; adopting the maximum membership principle and finding out the Bmax with the maximum component in the B vector,enabling the evaluation corresponding to the Bmax to serve as the result of fuzzy comprehensive evaluation,and achieving comprehensive evaluation of the exploitability of the barrier lake. According to the method,a fuzzy group decision-making method and a multi-level decision-making theory are introduced,a multi-level multi-factor decision-making weir dam exploitability argumentation mathematical model is established from three criterion layers of engineering safety risks,resource feasibility and ecological environment benefits,the exploitability of the weir dam is evaluated,and reference and guidance are provided for permanent regulation of the weir lake.