［Objective］ The spatiotemporal evolution of tourism eco-efficiency and its influencing factors were explored in ‘the Belt and Road Initiative’ （BRI） partner countries to provide scientific evidence for the sustainable development of tourism. ［Methods］ A tourism eco-efficiency indicator system was established， utilizing an input-output perspective. An improved four-stage Data Envelopment Analysis （DEA） model was adopted to measure the tourism eco-efficiency of 52 countries along the BRI from 2000 to 2021. Spatial autocorrelation and the Spatial Durbin Model （SDM） were utilized to analyze the spatial evolution characteristics， influencing factors， and spatial spillover effects of tourism eco-efficiency. ［Results］ ① Tourism eco-efficiency of the BRI countries exhibited an upward trend. ② There was significant spatial differentiation in tourism eco-efficiency development among BRI countries， with large disparities in values. ③ High-high agglomeration areas were primarily concentrated in China and its neighboring countries such as Thailand and Laos， aligning with general economic development patterns. Low-low agglomeration areas were mainly distributed in countries such as Saudi Arabia and Oman. Low-high and high-low agglomeration areas were relatively scarce. ④The urbanization rate and wealth level had significant positive impacts on tourism eco-efficiency， while the infrastructure level and population structure had significant negative impacts. Industrial structure and openness levels negatively impacted tourism eco-efficiency， although not significantly， with notable spatial spillover effects. ［Conclusion］ Certain factors significantly influenced the tourism eco-efficiency of BRI countries. Enhancing tourism eco-efficiency requires targeting these influencing factors while leveraging the driving influence of select BRI countries to promote the development of tourism.