Compared with conventional airborne remote sensing application to engineering geological investigation, High precision Unmanned Aerial Vehicle Remote Sensing (UAV-RS) technology can improve work condition with advantages of high flexibility, low cost, high efficiency and up-to-date situation acquisition. Especially, it has very important engineering significance for quick and urgent geological disaster reconnaissance along transportation lines. In the paper, some aspects of application to transportation-line (pipeline, highway and railway) engineering geological investigation were discussed. The concerned key points, including components of UAV-RS system, data processing workflow and image interpretation were analyzed. As a case study, a UAV-RS application project for transportation-line geological disaster investigation was given. The utilization of this new remote sensing technology successfully collected and discovered potential geological disasters and provided scientific data for timely decision-making.