Urban ecological space is the green base and ecological foundation of urban and rural development, which is synergistically linked to the ecosystems of "landscape, water, forest, field, lake and grass", and is the spatial carrier of various processes of flora and fauna and natural ecology, as well as the place for human socio-economic activities, and is closely related to urban and rural economic and social development. A good urban ecological space system is an important carrier to realize the stability of the ecosystem at the municipal level, to coordinate urban development and nature protection, and also an important guarantee to realize the healthy and benign development of the city. The existing municipal ecological spatial planning does not pay enough attention to its static, qualitative-oriented planning methods, which are seriously lagging behind, with a series of deficiencies and defects:1) emphasis on urban areas rather than municipalities; 2) emphasis on subjective qualitative rather than objective quantitative; 3) emphasis on passive implementation rather than active response; 4) emphasis on static blueprints rather than dynamic simulations. Its spatial planning results are far from meeting expectations and cannot cope with the impacts and threats brought by urbanization on the ecological environment and resources of the urban area. This paper selects Ningbo urban space as the object, takes the evolution of urban ecological space as the starting point, and reveals the characteristics and laws of the evolution of urban ecological space from three aspects:security pattern, structural characteristics and land use type transfer of ecological space, through the quantitative analysis of the evolution of urban space in 2000, 2010 and 2018. Based on this, we explore the methods and contents of the new municipal ecological space reconstruction and propose strategies for spatial optimization:to address the problems of declining ecological suitability at the security pattern level, declining connectivity at the structural level, and decreasing green space at the land type level, etc., by identifying ecological cores, organizing green space corridors, screening key nodes, grading and protecting them respectively, and finally reconstructing a benign Ningbo municipal ecological Spatial system of Ningbo city is reconstructed, and the optimization results are evaluated and revised. This study starts from the analysis of the evolution of three types of urban ecological space, and uses the logic of "evolution-response-reconstruction" to guide the urban ecological space planning, and actively explores a new method for optimizing the urban ecological space under the influence of urbanization, which provides a certain theory for the protection and scientific utilization of resources in the urban landscape, forest, field, lake and grass life complex.