Abstract:A comprehensive evaluation index system of river health was established from four aspects, including physical characteristics, hydrological regime, water environment quality and biodiversity. A mathematical model for comprehensive evaluation of river health was established based on composite fuzzy matter element and entropy weight method. A case study on the key sections of Huaihe River mainstream was carried out. The results show that the river health indexes of the four key sections of Huaibin, Wangjiaba, Lutaizi, and Bengbu in Huaihe River mainstream are 0. 470, 0. 435, 0. 462, and 0. 432, respectively. The comprehensive health level of the river is not high as a whole, showing a downward trend from upstream to downstream. Due to the influence of national policies and human activities, the health of the river of Lutaizi section has increased significantly.