Abstract: The report of the 20th CPC National Congress clearly puts forward that high-quality development is the primary task of building a socialist modernized country in an all-round way, adheres to the theme of high-quality development, and pushes the economy to achieve effective qualitative upgrading and reasonable quantitative growth. High-quality development has become the guiding ideology of China's socio-economic development and the topic of academia, and urban agglomerations, as the strategic highland of regional development, are facing the key task of “improving quality and increasing efficiency”. The article integrates the requirements of the 20th Party Congress on high-quality development and the five new development concepts of “innovation, coordination, greenness, openness and sharing”, constructs an evaluation index system of urbanization quality, reveals the spatial and temporal characteristics of urbanization quality in the Yangtze River Delta city cluster, and explores the urbanization quality of the Yangtze River Delta city cluster with the help of geographic probes. The study reveals the spatial and temporal characteristics of urbanization quality in the Yangtze River Delta urban agglomeration and explores its driving mechanism with the help of geographic probes. The results of the study show that: (1) the quality of urbanization shows a three-stage temporal evolution of “fluctuating improvement-steady improvement-significant improvement”, and the six dimensions of urbanization are: orderly coordination, green development, sharing and prosperity, economic support, openness, and innovation drive; The continuous and steady improvement of the quality of urbanization is mainly due to the orderly improvement of its coordinated development, the continuous optimization of the infrastructure level, the obvious improvement of the quality of public services, and the strong practice of the concept of green development, and in the future, efforts should be made to implement the innovation-driven strategy, and to expand the open economy in order to inject innovative vitality and new dynamic energy into the improvement of the quality of urbanization. (2) The quality of urbanization is characterized by the spatial pattern of “core-periphery” gradient with Shanghai, Nanjing and other central cities as the core; high-quality zones are core cities such as Shanghai, Nanjing and provincial capitals, while higher-quality zones are concentrated in the peripheral areas, and lower-quality and low-quality zones are distributed in the northwestern and remote inland areas of the Yangtze River Delta. The lower and lower quality districts are distributed in the remote areas in the interior of the Yangtze River Delta. (3) The quality of urbanization shows significant positive spatial correlation and the spatial agglomeration tends to increase; the local spatial autocorrelation is dominated by the high-high agglomeration type and the low-low agglomeration type. (4) The quality of urbanization is driven by multiple core factors, with the number of core factors increasing, the q value of the explanatory ability increasing year by year, and the interaction between the factors explaining the spatial and temporal characteristics of the spatial and temporal variations to a higher degree; the driving mechanism is a six-dimensional interaction with economic support as a lasting driving force, coordinated and orderly casting of a stable driving force, scientific and technological innovation and sharing prosperity as a subsequent driving force, and green development and openness as a potential driving force. Evolution. Based on this, relevant policy insights are drawn in order to provide a scientific basis and important reference for improving the quality of urbanization in the Yangtze River Delta city cluster and promoting the healthy, orderly and smooth development of urbanization.