Abstract: Based on the perspective of the theory of urban-rural continuum and the composite ecosystem, the connotation framework of the high-quality development of urban-rural integration was constructed. The measurement model, which included three levels of economy, society, ecology, was developed, incorporating the degrees the static integration and the dynamic coupling coordination. This study measured the high-quality development level of urban-rural integration in the 16 cities in the core area of the Yangtze River Delta from 2006 to 2021. The spatial and temporal evolution characteristics were explored and the major obstacles were identified. This study found that: （1） The high-quality development level of urban-rural integration had been growing steadily. The regional development gap narrowed first and then expanded. There existed a tendency of polarization, eventually forming a distribution pattern of "high in the west, low in the east, high in the north and low in the south". （2） The high-quality development form of urban-rural integration in the study area  included nine combination types from low to high. Some regions experienced a good transition from low-level I-I types to high-level III-III and III-IV types. However, there was a certain imbalance in the structure of static integration and dynamic coupling coordination, which blocked the continuous improvement of high-quality development level of urban-rural integration. （3） The major obstacle layer restricting the high-quality development of urban-rural integration was the social integration layer. The key obstacle factors were urban-rural population mobility structure, urban-rural information network density, urban-rural air quality and urban-rural healthcare equalization.