With the continuous growth of greenhouse gas CO2 emissions, climate change led by human activities has affected all regions of the world, so it is of great significance to scientifically and effectively grasp the temporal and spatial dynamics of regional carbon flow for regional mitigation of climate change and the realization of the "dual carbon" goal. In this study, we combined the available energy statistics and material flow analysis methods, took Hunan Province as an example, analyzed the carbon flow in the region, drew carbon flow maps in 2012 and 2020, and compared the carbon flow trend according to the total carbon flow, industrial sector and process carbon emissions. The results showed that the total energy-related carbon emissions in Hunan Province in 2012 and 2020 were 420.8039 million tons and 354.3196 million tons, respectively, which decreased by 30.34% in 2020 compared with 2012. In 2020, the total CO2 emissions of processes in Hunan Province were 72,216,400 tons, of which the CO2 emissions of ferrous metals, chemical industries and non-metallic mining processes accounted for 16%, 1% and 64% of the total CO2 emissions of the industry, respectively. This study can provide data reference and theoretical basis for the implementation of the "dual carbon strategy" of relevant regional departments.