Urban ecological carrying capacity reflects the maximum population capacity supported by urban ecological systems sustainably. As a matter of fact, land development and utilization are extensively and profoundly related to ecological carrying capacity due to its great role playing in resources, environment and economic growth. From the prospective of theoretical and practical value, it is highly significant to thoroughly investigate the influence and spatial patterns of land use efficiency on urban ecological carrying capacity. Theoretically speaking, this study systematically elucidates the direct impacts of land use efficiency on urban ecological carrying capacity as well as the spatial spillover mechanism. Empirically from an evidence-based perspective, in consideration of the panel data of 280 cities at prefecture-level and above in China from 2006 to 2022, this study centered the core objective on "the maximum population capacity that a city can carry sustainably", the comprehensive evaluation index system of urban ecological carrying capacity was constructed, starting from the following four dimensions of resource supply and consumption balance, environmental carrying and loading capacity, ecosystem services-health status, and socioeconomic development potential. Methodologically, the entropy weight TOPSIS method was employed to measure the urban ecological carrying capacity, while the spatial Durbin model was constructed to empirically examined the spatial effect of land use efficiency on urban ecological carrying capacity. For the view of academic and practical implications, key findings reveal as followed: (1) There was a certain degree of fluctuation in the ecological carrying capacity across different cities from 2006 to 2022, with an overall spatial pattern generally characterized by "high values in the southeast and low values in the northwest" during the study period. (2) Land use efficiency would exert a significant positive effect on the ecological carrying capacity of local city and the ecological carrying capacity of neighboring cities. (3) The direct effect of land use efficiency on the improvement of ecological carrying capacity might be more pronounced in eastern and western cities, as well as in those cities with low population density. Meanwhile, the spatial spillover effect on the enhancement of ecological carrying capacity could be more significant in eastern cities and resource-based cities. (4) Land resource misallocation substantially would inhibit the positive impact of land use efficiency on urban ecological carrying capacity. Based on the results above, this study provided empirical evidence for cities to enhance land use efficiency, optimize ecological carrying capacity, and promote sustainable development from an empirical and practical point of view.