[Objective] The connection of various ecological elements in urban and rural spaces on a mesoscale and the detailed optimization measures of the layout of ecological corridors of Harbin City was explored to realize the linkage between the urban and rural ecosystems, improve regional ecological benefits, and provide a reference for making decisions in relevant ecological planning departments.[Methods] Based on the principles of landscape ecology and GIS technology, important river corridors with large ecological resistance values were used as boundaries. According to the development trend of the city, the research scope of urban and rural spaces on a mesoscale was determined. Through an analysis of the land use changes of Harbin City during 1990-2017, the evolution of coupling modes of various ecological elements on the temporal and spatial scales was obtained, providing directions for the construction and optimization of ecological security patterns. The morphological spatial pattern analysis method was used to identify and evaluate the core area, bridge area, and island patches of the ecological elements of the study area, and important ecological sources were extracted based on the dPC index. Based on the minimum cumulative resistance model, potential ecological corridors were obtained and areas with weak connectivity were planned and supplemented through calculations. The width of the buffer zones of corridors, nuclear density, and ecological break point were obtained and the ecological security pattern was optimized in detail based on the temporal and spatial changes in the ecological coupling mechanism.[Results] Through the change in the coupling mode of various ecological elements on a mesoscale, ecological sources and the detailed optimization measures for the corridors in the urban and rural spaces of Harbin City were determined, and a stable and sustainable ecological security pattern was formed. In this research, the optimized construction measures were summarized according to local conditions.[Conclusion] Fifteen core areas in Harbin City are the original ecological sources, and there are 42 important ecological corridors and 63 general ecological corridors. The corridors are mainly distributed in the northern part of the study area. The optimized ecological security pattern complements 11 ecological sources and 220 potential planned ecological corridors, and the suitable construction width of a corridor is 60 m.