<p>Urbanization serves as an engine for economic development, yet the risk of “carbon lock-in” caused by infrastructure and consumption patterns threatens long-term sustainability. Studying the synergistic effects and regional differences between China’s new urbanization (NU) and zero-carbon strategies (ZCS) is a crucial economic and social issue for China to participate in global climate governance and achieve urban modernization. This study systematically analyzed the evolution law and regional differences of the coupling coordination degree (CCD) between NU and TFCEE by employing the entropy-weighted TOPSIS method, coupling coordination model, Dagum-Gini coefficient, and convergence model. The findings are as follows: (1) The coupling coordination level (CCL) between NU and Total-factor carbon emission efficiency (TFCEE) has been increasing year by year, with the eastern region taking the lead in forming intermediate coordination and maintaining a leading position; (2) In terms of intra-regional differences, the CCL in the eastern, central, and northeastern regions exhibit a fluctuating decline, whereas those in the western region demonstrate a fluctuating increase. In terms of inter-regional differences, the disparity between the eastern and western regions (east-west) stands out as the most prominent. Here, inter-regional variations play a primary role in accounting for the overall inequalities; (3) In the σ-convergence and β-convergence analyses, the spatial imbalance in the western region is more pronounced, indicating that although the western region has shown a positive catch-up effect, the absolute gap with the eastern region has not yet narrowed due to differences in initial conditions. In general, the CCD between NU and TFCEE is gradually optimizing, but the spatial imbalance remains prominent, especially in the western region, which urgently needs to be improved through targeted policy guidance.</p>