It is the consensus of many cities to cope with the challenges of global climate change and rapid urban development that the blue-green system should be used as the spatial infrastructure to coordinate urban ecology, economy, society, and other multi-objective development strategies. Understanding the evolution of blue-green space and its interaction with urban subsystems is the premise to promote the full play of the comprehensive functions of the blue-green system, but there are few existing studies. Based on the perspective of Spatio-temporal evolution analysis, this study takes Wuhan as an example. Firstly, the Spatio-temporal evolution of blue-green space in Wuhan from 1996 to 2018 is quantified through image interpretation. Secondly, the collaborative development evaluation model is introduced. The composite model of “blue-green system - urban economy - urban society” is constructed by extracting the characteristics of urban social economy and blue-green space. And each subsystem’s comprehensive development benefits and the hybrid system’s synergetic degree are measured. Results show that from 1996 to 2018, the area and fragmentation and heavy rains flood volume of the blue and green space in Wuhan city continued to decrease. Moreover, the coordination degree of the “economy - society - blue and green space” complex system increased. This trend is consistent with Wuhan’s urban economic development and ecological civilization construction, indicating that improving urban construction quality and implementing relevant protection measures help promote the coordinated development of urban subsystems. This paper puts the change in the morphology and structure of blue-green space in the background of urban development, quantifies the temporal and spatial variation of the morphology and structure of blue-green space, and discusses the process of its co-evolution with other economic and social factors of the city, in order to provide a reference for urban blue and green space sustainable planning and policy scientific formulation.