To study the spatial mismatching between water resources and associated elements, an adaptability evaluation method for water resources and associated elements, including resource layer, social layer, economic layer, and ecological layer, was proposed according to the adaptation theory and multi-dimensional attribute theory of water resources from the perspective of water network. Further, the method was applied to the affected area of the first phase of middle route of the South-to-North Water Diversion Project (SNWDP). The results showed that the proposed method can reveal adaptation characteristics of water resources and associated elements reasonably and systematically. The spatial distribution of water resources and associated elements was relatively reasonable in the affected area of the first phase of middle route of the SNWDP for the period 20162020, with an overall Gini coefficient of 0.388. Water resources and associated elements showed good spatial adaptability in resource layer and social layer, with Gini coefficients of 0.283 and 0.284, respectively. However, serious mismatching between water resources and associated elements occurred in economic layer and ecological layer, with Gini coefficients of 0.501 and 0.486, respectively. With the implementation of water transfer in the first phase of middle route of the SNWDP, the spatial adaptability of water resources and associated elements in resource layer, social layer, and economic layer has been improved in different degrees, while ecological layer has little change in spatial adaptability.