Abstract: Rapid and accurate quantitative investigation and evaluation of landslides can provide scientific basis for the emergency treatment of landslide, and the unmanned aerial vehicle (UAV) aerial photography system has become a reliable means for geological disaster investigation due to its flexibility and rapid response. In this paper, the Pingqing landslide in Ceheng is taken as an example, and a set of processes of rapid slope investigation and quantitative evaluation based on the light UAV aerial photography technology are summarized. The path of establishing high-precision 3D geological model using various software is expounded, and the finite difference method (FDM) is applied to analyze the deformation mechanism and evaluate the stability of the landslide. The results show that (1) the Global mapper, Pix4Dmapper, Rhinoceros and other software are used to manage the data acquired by UAV and to establish a 3D model, which is convenient, rapid and reliable. (2) In the procedure, landslide investigation and evaluation based on UAV, the traditional qualitative analysis is combined with the quantitative analysis by means of numerical simulation, which can provide convincing basis and supporting data for emergency after. (3) The Pingqing landslide in Ceheng is a creepage-pull crack landslide caused by gravity stress of slope body under rainfall condition. At the period of investigation, the landslide had activated and the surface cracks had tended to expand rapidly.