The purpose of this study is to explore the spatial and temporal evolution characteristics of carbon emission inequality in China at the spatial grid scale, providing effective pathways for formulating more targeted and refined policies to reduce carbon inequality. Based on the spatial allocation of carbon emissions and human well-being using a distribution model and window analysis, the spatio-temporal evolution characteristics of carbon inequality were analyzed, and potential policy recommendations for reducing carbon inequality were proposed. The results indicate that from 2000 to 2020, the national carbon emissions and human well-being both showed an overall upward trend. However, while the growth rate of carbon emissions declined, the growth rate of human well-being remained stable. Carbon emissions exhibited a clustered and spatially expanding distribution pattern, with provincial capitals and metropolitan areas demonstrating significantly higher emission levels compared to small cities and rural regions. Similarly, high-value zones of human well-being showed continuous outward expansion, with particularly concentrated distributions in densely populated areas. The carbon Gini coefficient exhibited an increasing trend, with high-value regions predominantly concentrated in Northeast China, as well as some provinces within Central and Southwest China. The uneven distribution of carbon emissions and human well-being has led to worsening regional carbon inequality. Furthermore, the spatial mismatch between high-carbon emission zones and high human well-being benefit areas has exacerbated nationwide carbon inequality. The research findings provide new insights for exploring the spatial distribution of carbon inequality and also serve as a basis for the formulation of climate policies.