Tourism ecological efficiency serves as a core metric for assessing the quality of tourism development, comprehensively considering both economic benefits and environmental impacts. With the thriving tourism industry along the countries involved in the Belt and Road Initiative (BRI), promoting its green and low-carbon transformation as well as deepening international cooperation and exchanges have emerged as new focal points. This study, grounded in tourism input-output data spanning from 2000 to 2021 for 52 BRI countries, conducts an in-depth analysis of these countries" tourism ecological efficiency. By employing an improved four-stage DEA index for quantitative analysis, along with Moran"s I index, LISA visualization techniques, and the Spatial Durbin Model, we systematically explore the temporal and spatial evolution characteristics, key influencing factors, and spatial spillover effects of tourism ecological efficiency. The results indicate that: (1) The overall tourism ecological efficiency index along