Abstract: Aiming at the problems existing in the selection of evaluation index of water resources carrying capacity, it proposes to establish the evaluation index system of water resources carrying capacity according to the regional characteristics, and then apply the grey correlation analysis method to reduce each index,so as to set up a concise and practical evaluation index system of water resources. Taking Zhengzhou city as an example, the preliminary establishment of water resources carrying capacity index system and the specific methods of index reduction are discussed.