国家“双碳”目标背景下，适度的紧凑是黄河流域城市绿色低碳高质量发展的最佳选择。以黄河流域77个地级市为例，多维度构建综合评价指标体系，基于熵权法、综合加权求和模型、核密度估计、双变量空间自相关分析、时空地理加权回归模型和地理探测器等方法，分析2005—2021年黄河流域城市紧凑度对碳排放绩效的影响。结果表明：（1） 2005—2021年黄河流域城市紧凑度与碳排放绩效均略有提升，分别呈现“上中游低、下游高”“中游低、上下游高”的空间分布格局。（2） 2005—2021年黄河流域内城市紧凑度与碳排放绩效的关联性具有明显的时空差异，多呈空间负相关性，且呈空间负相关性的城市数量增多，呈空间正相关性的城市多位于中下游地区。（3） 2005—2021年黄河流域城市土地利用紧凑度和人口紧凑度对碳排放绩效的负向影响较为明显，土地利用紧凑度负向影响减弱，人口紧凑度在中上游地区负向影响增强但在下游地区负向影响减弱；经济紧凑度和交通紧凑度对碳排放绩效主要为正向影响，但交通紧凑度在上下游地区负向影响区均增多。（4） 2005—2021年黄河流域城市紧凑度与其他社会经济因子交互后对碳排放绩效的影响均增强，各因子协同作用共同影响碳排放绩效，其中经济紧凑度和能源消耗水平协同作用影响最大。未来，该流域应通过因地制宜实施差异化的城市紧凑发展策略、优化产业结构、提升城镇化质量、强化低碳技术创新和加强城市紧凑度动态调控等方式，促进经济增长、社会福利提升与低碳减排的协同发展。

Under the framework of China’s “double carbon” goal, moderately compact urban development is considered the optimal approach for achieving green, low-carbon, and high-quality growth in the Yellow River Basin. Considering 77 prefecture-level cities in the Yellow River Basin as examples, this study constructed a comprehensive evaluation index system across several dimensions such as population, economy, and society. Employing the entropy weight technique, comprehensive weighted summation model, kernel density estimation, bivariate spatial autocorrelation analysis, spatiotemporal weighted regression model, and a geographical detector, this study analyzed the effects and mechanisms of urban compactness on carbon emission performance in the Yellow River Basin from 2005 to 2021. The results are as follows. (1) From 2005 to 2021, both the urban compactness and carbon emission performance in the Yellow River Basin slightly increased. Urban compactness exhibited a spatial distribution pattern of “lower in the upper and middle reaches, and higher in the lower reaches”, whereas carbon emission performance exhibited a pattern of “lower in the middle reaches, and higher in the upper and lower reaches”. (2) The correlation between urban compactness and carbon emission performance varied significantly across time and space in the Yellow River Basin from 2005 to 2021. Most cities demonstrated a negative spatial correlation, with the number of such cities increasing over time in the Yellow River Basin. Cities of the Yellow River Basin with positive spatial correlation between urban compactness and carbon emission performance were mostly located in the middle and lower reaches. (3) The negative impacts of land use compactness and population compactness on carbon emission performance were relatively obvious in the Yellow River Basin from 2005 to 2021. The negative impact of land use compactness weakened. For population compactness, the negative impact increased in the mid-upper reaches regions but weakened in the downstream regions. The economic compactness and transportation compactness mainly had positive impacts on carbon emission performance, yet the areas with negative impacts of transportation compactness increased both in the upstream and downstream regions. (4) The influence of urban compactness on the carbon emission performance was enhanced when interacting with other socioeconomic factors in the Yellow River Basin from 2005 to 2021. Synergies among various factors considerably affected the carbon emission performance. The greatest combined effect was observed between the economic compactness and energy consumption levels. Thus, to promote coordinated development in the Yellow River Basin, differentiated urban compact development strategies must be implemented based on regional conditions. Further, efforts should focus on the optimization of industrial structures, improvement of urbanization quality, fostering of low-carbon technology innovation, and dynamic adjustments of urban compactness. These measures are aimed at promoting balanced economic growth, social welfare, and low-carbon development across the entire basin.