Abstract: The top of the high-steep slope are usually arduous and unreachable, the identification and evaluation of high position geological disaster are the difficult problem in the disaster prevention. Based on a typical high and steep slope and aided by the unmanned aerial vehicle photograph, to identify the geological characteristics of potential unstable rock mass and deformation rock mass on the top part of the steep-slope. Digital photogrammetry technology were used to obtain the information of the rock mass structure and the geometric characteristics. Studied the stability of the potential unstable rock mass, trajectory of the falling rock mass and the impact energy, then the slope geological hazard were evaluated. Vulnerability analysis and economic loss calculation after disaster of the three types of structures, such as bridge, subgrade, shed tunnel, showed that the shed tunnel is the best, and if the other structures are used, it is necessary to reinforce the slope.