Spatiotemporal evolution and driving factors of coupling coordination between new-type urbanization efficiency and the ecological environment in Southwest China’s ethnic minorities areas

New-type urbanization reflects a development orientation toward low-carbon, green, and environmentally friendly growth; however, its relationship with the ecological environment remains insufficiently understood, particularly in ecologically fragile and underdeveloped regions. Taking the Southwest China’s ethnic minorities areas as the study area, this paper employs Data Envelopment Analysis (DEA), the Slacks-Based Measure Data Envelopment Analysis (SBM-DEA) model with undesirable outputs, the entropy method, the Coupling Coordination Degree (CCD) model, and the panel random-effects Tobit model to evaluate new-type urbanization efficiency, the ecological environment index, and their coupling coordination relationship from 2010 to 2021. The results show that, without considering undesirable outputs, new-type urbanization efficiency remains generally high, whereas the Slack-Based Measure results reveal clear efficiency losses once environmental pollution is incorporated. The ecological environment index increases steadily, and the coupling coordination degree shows an overall upward trend after a slight early decline, suggesting that ecological improvement partially offsets efficiency losses caused by undesirable outputs. In the panel random-effects Tobit model, industrialization is negatively associated with the coupling coordination relationship and is the only factor that reaches marginal statistical significance, while environmental governance and technology investment show positive but statistically weak directional associations. The findings indicate that, in Southwest China, coordinated development between new-type urbanization and the ecological environment depends less on expansion speed than on industrial upgrading, environmental governance, and resource-use efficiency under ecological constraints. The study contributes to coupling coordination research by combining conventional and environmentally constrained efficiency measures in an ecologically fragile and underdeveloped minority region, and provides bounded policy implications for similar regions.