Promoting green and low-carbon development according to local conditions was an important strategic guidance for China's ecological civilization construction and the achievement of its "dual carbon" goals, holding significant practical value for developing differentiated regional carbon management and spatial zoning strategies. This study analyzed the spatial differentiation characteristics of the carbon budget across 122 districts/counties in Hunan Province using economic contributive coefficient and ecological support coefficient. Building on this analysis and integrating existing major function-oriented zones (MFOZs), we proposed a framework of dual-carbon spatial management units that couples regional carbon budget zoning with MFOZs. This provided a scientific basis for implementing spatially targeted carbon management policies. The results showed that: ①From 2000 to 2022, the carbon emissions and carbon absorption in Hunan Province showed an upward trend, with 32113.51×10⁴ t and 45179.35×10⁴ t in 2022, respectively. The areas with high carbon emissions continued to expand, while the carbon absorption areas remained relatively stable overall. ②The carbon zoning results based on the economy contributive coefficient and ecological support coefficient indicated that there were 82, 23, 15, and 2 Low energy carbon sink zones, High energy carbon emission zones, Low energy carbon emission zones, and High energy carbon sink zones in Hunan Province, respectively. Low energy carbon sink zones (67.21%) were mainly located in the hilly forest area around Hunan Province, while the number of High energy carbon emission zones (18.85%) and Low energy carbon emission zones (12.30%) were mainly located in in the economically developed central districts and counties such as Changsha, Zhuzhou, Xiangtan and Hengyang. ③Coupled with the results of the "carbon budget zoning-major function-oriented zones", the districts and counties of Hunan Province divided into 11 types. Among them, the "Low energy carbon sink-National key ecological function zone" was the most important type (38 districts and counties, a total of 85212 km²). It was mainly located in Zhangjiajie City, Huaihua City, Xiangxi Tujia and Miao Autonomous Prefecture, Yongzhou City, Chenzhou City and other western and southern districts with high vegetation coverage. While "Low energy carbon emission-Provincial urbanized zone" (1 district and county, 137 km²) had the smallest unit type, mainly located in Shuangqing District of Shaoyang City. The research results provided research foundation and spatial support for the strategy of "Promoting green and low-carbon development according to local conditions", and contributed to the realization of the dual carbon strategy.