The Yangtze River Economic Belt is a vital ecological security barrier and the focus of China's economic development. Promoting the construction of urban agglomerations in the Yangtze River Basin is crucial for accelerating the development of the Yangtze River Economic Belt. The five urban agglomerations in the Yangtze River Economic Belt were used as the research objects; their environmental carrying capacities and the coupling relationship between these capacities and urban agglomeration development were explored. Based on the results, we categorized these urban agglomerations into three types: (1) mature-environmental overload type constituting the urban agglomeration in the Yangtze River Delta, (2) high-speed development-environmental overload type, comprising the urban agglomerations in Chengdu-Chongqing and the middle reaches of the Yangtze River, and (3) cultivation-environmental non-overload type that comprised the urban agglomerations in central Guizhou and central Yunnan. Herein, we propose strategic suggestions for the development of urban agglomerations in the Yangtze River Economic Belt considering the aspects of ecological space control, optimization of spatial land patterns, green development of urban agglomerations, and improvement of the human settlement environment. These aim to strengthen the guiding role of environmental carrying capacity in developing urban agglomerations and provide basic support for promoting high-quality development of the Yangtze River Economic Belt.