Abstract: The achievement of green total factor productivity (TFP) growth is an important way for the Yangtze River Economic Belt (YREB) to practice green and low-carbon development and achieve high-quality development. This study took the measured green TFP of the YREB from 2005 to 2020 as the research object, and used the methods of spatial distribution map and standard deviation ellipse to explore the temporal and spatial evolution and agglomeration characteristics from the perspective of urban agglomeration. The driving factors of the spatial differentiation of green TFP were studied by means of geodetector. The results showed that: (1) From 2005 to 2020, the green TFP of the whole YREB, the middle reaches of the Yangtze River city cluster and the Chengdu-Chongqing city cluster showed a development trend of a first decline and then an increase. The Yangtze River Delta city cluster showed a development trend of a first growth and then a decline and then an increase. (2) The green TFP of the YREB showed a spatial pattern of "Yangtze River Delta urban Agglomeration > Chengdu-chongqing urban Agglomeration > Urban agglomeration in the middle reaches of the Yangtze River "and" Central City > Non-central city; (3) The green TFP of the Yangtze River Delta urban agglomerations and the middle reaches of the Yangtze River experienced an evolutionary process of "first decentralization, then agglomeration". The agglomeration development characteristics of the green TFP of the Chengdu-Chongqing urban agglomerations were not obvious, but there was an obvious trend of migration to the east, and the central cities had a greater impact on the distribution pattern of green TFP. (4) The single factor detection results showed that urban development level, technological innovation and environmental regulation level were the core driving factors of the spatial differentiation of green TFP. The interactive detection results showed that the interaction of driving factors was greater than that of single factors, and the interaction of digitalization level and environmental regulation level in 2020 had the strongest interpretation of green TFP.