Abstract: The coordination degree of water resources development and protection and green development is of great significance for the high-quality development of the Yangtze River Economic Belt. This paper conducted a comprehensive study on the composite relationship between water resources development and protection and green development. The DPSIR model was used to construct the evaluation index system of water resources development and protection and green development. This paper also adopted the global entropy concept and the obstacle degree diagnostic method to identify the coupling coordination degree of water resources development and protection and green development and to explore the main influencing factors. The results showed that the overall level of water resources development and protection in the Yangtze River Economic Belt from 2015 to 2019 was low, and the level of green development was rising. The spatial distribution of water resources development and protection level and green development level showed the imbalance of “high in the east and low in the middle and west”. The coupling coordination degree showed an increasing trend. In 2019, the coupling coordination degree was at the intermediate coupling stage in Shanghai (0.714), Jiangsu (0.739) and Zhejiang (0.693). The overall spatial distribution showed a trend of “high in the north and low in the south, high in the east and low in the west”. In 2019, the obstacle factors from the water resources development and protection system accounted for 75%, including annual afforestation area and urban water conservation. Overall, the coupling coordination degree was greatly affected by human activities and resource endowment.