Considering the lack of evaluation index of large cross-regional waterway network connectivity of main and tributary waterways of the Yangtze River,by using the method of dividing major sections and selecting major indexes,we divided the Yangtze River main and tributary waterway network into 7 sections through field investigation,and evaluated the connectivity of the Yangtze River main and tributary waterway network by taking the density of equivalent grade of net-waterway and the degree of connectivity of net-waterway as the main evaluation indexes.It is found that the evaluation index can not only objectively and reasonably reflect the technical characteristics of large-scale waterway network,but also has some economic evaluation functions.It realizes the rapid evaluation of the connectivity of the waterway network in the main stream and tributaries of the Yangtze River,and effectively solves the selection of evaluation index for the connectivity of large-scale waterway network.It has certain applicability and generalization.