In 2021,large-scale full-line resumption of navigation on the Wujiang River was realized for the first time,and the upgrade to Class Ⅲ waterway standard for its Guizhou reach is being advanced.Aiming at the problems including insufficient multi-dimensional quantitative evaluation and unclear impact mechanism of navigation resumption and waterway class upgrade on the basin economy,this study establishes a systematic analysis framework covering transportation,economy,society and ecology,and adopts the “with-and-without” comparison method and input-output method for quantitative analysis.The results show that the waterway class upgrade of the Wujiang River can reduce social logistics costs,with transportation expenses expected to be reduced by 2.15 billion CNY in 2035 and 2.56 billion CNY in 2050.It can boost regional economic growth,generating a total economic value added of 10.98 billion and 19.4 billion CNY over the operation period.The project can create 80,000 permanent jobs,and drive approximately 149,000 jobs during construction and 263,000 jobs during operation.In terms of energy conservation and emission reduction,carbon emissions will be reduced by 379,000 tCO2 in 2035 and 498,000 tCO2 in 2050.The waterway class upgrade of the Wujiang River is a key measure to boost the comprehensive development of the basin economy.It is necessary to accelerate waterway upgrading,improve port hub functions,revitalize shipbuilding and strengthen policy support,so as to promote the coordinated development of transportation,economy,society and ecology in the basin.