Abstract: The construction of green and smart city clusters is the product of the coordinated development of urbanization, digitalization and greenization. The Yangtze River Economic Belt (YREB) serves as an important demonstration region in China. This paper explored the spatiotemporal evolution characteristics and the influencing factors of the coupling coordination development of urbanization, digitalization, and greenization in the YREB. The panel data from 108 cities in the YREB from 2005 to 2022 were collected. The methods of the coupling coordination model, the spatial Markov chain, the spatial Durbin model, and the geographical detector were employed. The results showed that: (1) In terms of temporal evolution, the degree of coupling coordination of the YREB had been increasing year by year, but the urbanization development was ahead of digitalization and greenization for a long time. In terms of spatial evolution, the spatial differentiation of the degree of coupling coordination was obvious, which manifested itself as a “stepped rise” from west to east; (2) There existed a “club convergence” phenomenon in the dynamic evolution of the degree of coupling coordination, which made it difficult to achieve leapfrog development across levels; (3) The development of the degree of coupling coordination was the result of the internal and external multi-dimensional drive of the economic support, resource promotion, government orientation, market pulling force, and social promotion.