Clarifying the spatiotemporal changes in carbon surplus and deficit and their driving factors is an important basis for formulating low-carbon economic development strategies and orderly promoting the dual carbon goals. The Chang-Zhu-Tan metropolitan area is the core growth pole of Hunan's economic development and the region with the strongest population carrying capacity. How to promote green and low-carbon transformation and ecological environment protection has become a practical problem faced in the development process. Based on the carbon emission coefficientmethod and improved CASA model, the carbon sources and sinks of the Chang-Zhu-Tan metropolitan area wereestimated in 2005, 2010, 2015 and 2020. Then, spatial autocorrelation, standard deviation ellipse, geographic detector and GWR model were used to analyze the spatiotemporal changes and driving factors of carbon surplus and deficit in the metropolitan area. The results showed that: (1)During the research period, the overall carbon surplus and deficit of the Chang-Zhu-Tan metropolitan area was in a state of carbon deficit and displayed an increasing trend year by year, but the changing trends varied significantly among different districts and counties. The carbon deficit in Furong, Kaifu, Liuyang, Ningxiang, and Liling showed an increasing trend followed by a decreasing trend, while the carbon losse in Lukou continued to decline. (2) From a spatial perspective, the carbon deficit showed a decreasing pattern from the central to the surrounding areas, and the center of carbon surplus and deficit continued to move towards the northwest direction of the geometric center. Overall, the carbon surplus and deficit of the county showed a significant spatial positive correlation, but exhibited a clustering characteristic of unbalanced development in local space. (3)Among the factors that affect the carbon profit and loss of the Chang-Zhu-Tan metropolitan area, annual solar radiation (ASR), per capita gross domestic product (PGDP), and energy intensity (EI) were the important factors affecting carbon surplus and deficit; population size (PS), urbanization level (UL), industrial structure (IS) and green coverage area (GCA) played secondary roles. The impact of PGDP and ASR on carbon profit and loss showed a trend of first strengthening and then weakening, the impact of PS, IS, and EI indicated a characteristic of first weakening and then strengthening, while the impact of GCA and UL had been decreasing year by year. There was spatial heterogeneity in the impact of various factors on carbon surplus and deficit. PGDP, EI, UL and IS promoted carbon deficit, while ASR and GCA inhibited carbon deficit. GCA had the strongest spatial heterogeneity in its impact on carbon loss; while EI had the weakest spatial heterogeneity. The above results can provide reference for low-carbon development and ecological protection in the study area.