On the basis of the needs of national land space integration theory and method, the paper explores the system optimization method of urban ecological space adapting to the local development characteristics of China's rapidly urbanized areas. (1) Firstly, from the perspective of landscape or land composition based on CHANS (coupled human and nature system), the elements of urban ecological space system are deconstructed as ecological space and urban space. Then, the process framework of urban ecological space conflict analysis is established, which includes three aspects: conflict source, conflict area and conflict impact. The conflict source refers to the driving force of urban spatial growth and the source of ecological spatial change. The pressure of urban spatial change on ecological space results in the formation of ecological spatial conflict area under the conflict source. The consequences of various urban ecological functions (processes) are caused by conflict factors and conflict areas. Lastly, the way of system optimization is proposed based on the systematic diagnosis of conflict process and causes. (2) The case study of rapid urbanization shows that the first conflict source of social and economic activities in urban ecological space conflict is not prominent, and the policy driving force constitutes the main conflict source and runs through the whole conflict process. Through the analysis of road network and land layout planning process, the type and conflict mechanism of conflict area between urban and natural catchment areas are revealed, and the SWMM model is used to simulate and identify four flooding types and key causes. (3) Therefore, the system optimization objectives of urban ecological space are constructed respectively for conflict sources, conflict areas and conflict impact. The traditional optimization objectives aim at the drainage process and facilities formed by end-conflict impacts, and the core objectives aim at the key causes of formation of flooding areas, i.e. the enhancement of storage function and reconstruction of spatial elements in conflict areas of urban ecological space change. The fundamental optimization objectives aim is to change system, policy and planning of urban ecological space. The spatial optimization framework consisting of three types of main functional optimization areas, six types of key points and five types of key channels is identified for the case area. The framework of conflict analysis and the method of system optimization in the paper provide reference for the study of national land spatial integration. The case study covers the succession process of international stormwater management as a whole, which is helpful for the local understanding of the current large-scale land development transformation and the concept of sponge city construction.