Abstract: The paper uses the entropy method – TOPSIS model to evaluate the urbanization and ecological environment development levels of 108 cities along the Yangtze River Economic Belt from 2008 to 2017, and uses the Gini coefficient and the Theil Index to evaluate the level and composition of urbanization development among and within cities in the three major urban agglomerations along the Yangtze River Economic Belt. The results show that, from the temporal perspective, the overall development level of urbanization quality in the Yangtze River Economic Belt has not been high in recent years, and the development differences have gradually decreased; from the spatial perspective, the overall urbanization quality development level of the three major urban agglomerations has shown a change from the economic belt. The trend of decreasing from east to west to the center is the spatial pattern of “Yangtze River Delta Region> Pan-Chongqing Region>Middle Delta Region”; the reduction of the overall difference is conducive to the reduction of the difference between the three major urban agglomerations, and the difference within the urban agglomeration expansion will slow down the trend of total difference reduction; the comprehensive development of the three major urban agglomerations in the Yangtze River Delta, the Middle Delta, and the Pan-Chongqing City will show certain differences.