Under the framework of sustainable urban development, it is crucial to realize regional carbon balance, the core of which is to grasp the balance between the type of urban land use structure and ecological land layout. This balance is not only related to the quality of the ecological environment of the city, but also has a direct impact on the city’s carbon emission and carbon storage capacity. Therefore, it is of profound significance to construct a scientific and reasonable spatial pattern of urban carbon sinks according to local conditions, in order to promote urban carbon balance and improve the quality of urban ecological environment.Taking the central city of Nanning as the study area, it constructed the spatial pattern of urban carbon sinks through the theoretical framework of “patch-substrate-corridor” in the ecological network technology, and comprehensively analyzed the landscape pattern of the urban carbon sinks and the net carbon sinks of the land. Based on the ArcGIS 10.6 working platform, the land use types in the study area were reclassified, and forest land, grassland, water body, shrubland and wetland, which are capable of generating natural carbon sinks with high carbon storage capacity, were taken as the foreground, while cropland, man-made surface and bare land were taken as the background, and the Morphological Spatial Pattern Analysis (MSPA) was used to obtain seven landscape types, which were used to identify the habitat patches that play an important role in the landscape connectivity in the study area. In order to accurately identify the habitat patches that play an important role in landscape connectivity in the study area, and whose analysis results can directly show the structural elements such as the area of the core area and the number of corridors, the core area was identified as a potential carbon sink, and landscape connectivity analysis was carried out for this landscape type to extract the spatial ecological source of carbon sinks. Based on the Minimum Cumulative Resistance (MCR) model, in order to realize the systematic and complete ecological network, it selects the resistance factors that have a high degree of relevance to the ecological source of carbon sinks, such as elevation, slope, NDVI, and the current state of land use to construct the resistance surfaces, and combine them with the gravity model to identify the importance of the carbon sink sites and carbon circulation corridors, and then identify the key corridors, so as to construct the urban carbon pool network. Through the identification and analysis, the results obtained: 1) the main land types of carbon sink space ecological source land in the study area are forest land and grassland; 2) the total area of carbon sink space ecological source land is 1 380.87 km2 , which accounts for 21.49% of the total area of the study area, and it is mainly distributed in the south and north of the study area, and it contains 11 key carbon sinks, 16 important carbon sinks, 21 key carbon sink corridors, and 23 important carbon sinks. The total area of the study area is 131.15 km2 , accounting for only 2.03% of the total area of the study area; 3) The spatial pattern of carbon sinks in the study area consists of carbon sink ecological sources, carbon sink corridors and the minimum cumulative resistance surface of carbon sinks, and it cansolve the problem of ecological security of carbon sinks in the region, and improve the level of ecological security of carbon sinks in the whole region. The level of ecological security of carbon sinks in the whole region will be improved.The construction of the spatial pattern of carbon sinks in Nanning City based on the perspective of carbon balance takes into full consideration the actual situation of the main urban area of Nanning City, and theoretically provides strong support for the realization of the city’s carbon balance. With the gradual implementation and improvement of the spatial security pattern of carbon sinks, Nanning City will achieve more significant results in realizing the urban carbon balance and improving the quality of ecological environment. This study does not only provide a specific planning program for the spatial pattern of carbon sinks for Nanning City, but also provides experiences and ideas for other cities and even the global urban carbon balance and sustainable development, and the results of the study are intended to provide theoretical support for the work of Nanning City’s territorial spatial security and construction.