[Objective] The synergistic relationship between land use carbon balance and human activity intensity were studied in order to provide a reference for regional collaborative carbon emission reduction planning in the Tuojiang River basin, and thereby meet the goal of "carbon peak and carbon neutrality" in China.[Methods] Using land use and socio-economic data from 2000 to 2020, carbon emission economic contribution coefficient, carbon ecological carrying coefficient, human activity intensity indicators, a coupled coordination model, and regression analysis, we calculated carbon emissions from land use in the Tuojiang River basin. We then analyzed the spatiotemporal evolution characteristics and synergistic relationship between land use carbon balance and human activity intensity.[Results] Carbon emissions in the Tuojiang River basin increased by 5.13×10⁷ t from 2000 to 2020, with construction land accounting for over 90% of carbon emissions. The small change in carbon absorption mainly resulted from forest land showing a change pattern of initially decreasing and then increasing. The growth rate of net carbon emissions showed a downward trend. The coordination of land use carbon balance in each district and county was improving, but more than 70% of the region was in a state of imbalance and decline. The overall intensity of human activities in the Tuojiang River basin was at a moderate level, with a spatial pattern of "low-high-low-high" from north to south.[Conclusion] There was a significant positive correlation between human activity intensity and per capita GDP and per capita carbon emissions. The negative correlation between land use carbon balance coordination and human activity intensity decreased with technological progress and increased energy utilization efficiency. Improving carbon sequestration capacity and carbon productivity is an effective way to improve the coordination level of regional land use carbon balance. The results of this study provide a reference for regional collaborative carbon emission reduction planning in the Tuojiang River basin.