With the transformation of China's urbanization, how to measure the coupling and coordination relationship between population, land and economy in the process of urbanization, and explore the temporal and spatial dynamics of its evolution process, has become an important scientific issue in the study of new urbanization in human geography. By constructing the model of coupling coordination degree, based on the coordinated development level of each subsystem in the process of urbanization in the Yangtze River Delta in the past 16 years, this paper analyzes the interaction process of urbanization coupling coordination, and explores the coupling mechanism of the formation of urbanization coordination space agglomeration in the study region by using spatial variogram, LISA time-space transition and other methods. The results show that: (1) with the remarkable improvement of population, land and economic urbanization level in the region, the evolution of the overall and the coupling coordination of population-land urbanization, land-economy urbanization and population-economy urbanization degree shows a steady convergence phenomenon; (2) the spatial agglomeration degree of the coupling coordination degree of urbanization is increasing year by year, and the scope of spatial correlation has been expanding continuously, basically forming a spatial pattern of "one pole alone, triangle core, peripheral low-level"; (3) from the perspective of the urbanization coupling level transition path of each city, most of the cities show a synergistic growth trend, indicating that the overall coupling coordination degree has obvious path dependence and space locking characteristics; (4) the evolution of urbanization coupling coordination level from the stability and equilibrium to polarization agglomeration state mainly comes from the interaction of land-economy, and the evolutionary power from polarization to equilibrium state comes more from population-land interaction. The study of the interaction process and mechanism of urbanization coordination provides a theoretical basis and direction for the construction and coordinated development of the Yangtze River Delta urban agglomeration.