In order to provide a scientific basis for the construction of “sponge city”, combined with the shortcomings of the existing methods, this paper proposes a variable weight PROMETHEE model based on AHP (Analytic Hierarchy Process) to comprehensively evaluate the present situation of rainwater utilization in different regions. Based on the six evaluation indexes of rainwater utilization, the model determines the initial weight with AHP and uses variable weight analysis. Then, the PROMETHEE evaluation model is established to evaluate the present situation of rainwater resources utilization in four different regions of Yunnan Province synthetically, and the advantages and disadvantages were ranked. The results show that the utilization of rainwater in region 2 is the best, followed by region 3 and region 1, and region 4 is the worst. At the same time, the evaluation results of the model proposed in this paper are compared with the existing two methods, which reflects the rationality and superiority of the model. In addition, this paper also gives some suggestions for improvement in four different regions, which is instructive for the improvement of subsequent rainwater resources utilization in these regions.