[Objective] The spatial land use resources of Changsha-Zhuzhou-Xiangtan urban agglomeration were optimized from the perspective of carbon balance, in order to provide theoretical support for the sustainable development of the region’s society and economy. [Methods] The carbon sinks and carbon emissions of the Chang-Zhu-Tan urban agglomeration were calculated from a land use perspective. Using the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, carbon balance zoning was conducted, and land use optimization strategies were proposed for each type of city and county. Economic benefits, carbon sink benefits, compactness, and conversion costs were set as optimization functions for a multi-objective algorithm, achieving a more scientific optimization of land use spatial structure using the CoMOLA model. [Results] ① From 2000 to 2020, the total carbon emissions of the Chang-Zhu-Tan urban agglomeration increased annually, while the carbon sink levels in various districts and counties remained relatively stable, with an overall slight decline. ② Based on the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, the Chang-Zhu-Tan urban agglomeration was classified into carbon sink development zones, economic development zones, comprehensive optimization zones, and green development zones. ③ The optimized land use increased economic benefits by 28.5%, carbon sink volume by 4.2%, and compactness by 3.6%. [Conclusion] The optimized land resources effectively meet the needs for economic and ecological sustainable development in the Chang-Zhu-Tan urban agglomeration, with a more rational spatial arrangement of land. This provides a decision-making basis for future land resource allocation.