As an important ‘bridge’ of China's western development strategy, the Sichuan-Tibet Railway is of great importance to the social and economic development of Tibet. In order to enhance regional geological disaster prevention and control capabilities and assess socio-economic development potential. In this paper, 33 counties along the Sichuan-Tibet Railway were selected as the study area, and 12 indicators were selected from four levels: geomorphological environment, geological environment, ecological environment and social environment to build the evaluation index system of geo-environmental carrying capacity, and the weights of each indicator were determined by random forest model, and GIS spatial analysis was used to evaluate the geo-environmental carrying capacity of counties along the Sichuan-Tibet Railway. (1) the geological environment quality of the counties along the Sichuan-Tibet Railway is generally good, and the area of medium quality or above accounts for more than half, and the area of poor quality is mainly concentrated in the area of Basu County and Chaya County, which accounts for a relatively small area; (2) the overall geo-environmental carrying capacity along the Sichuan-Tibet Railway is influenced by the regional geological background, i.e., engineering rock groups and active faults, followed by the geo-environmental carrying capacity represented by NDVI. Therefore, it is suggested that on the basis of monitoring fault activities and controlling engineering activities along the line, ecological protection and restoration along the line should be paid attention to in order to maintain the development "dividends" brought by the Sichuan-Tibet Railway and ensure the sustainability of development.