The new technology of UAVs low-altitude photogrammetry is a new three-dimensional space technology after radar remote sensing and 3D laser scanning. This technology has many advantages in the aspect of acquiring 3D point cloud data, such as large area operation, high-accuracy and capturing 3D geographical information quickly. With the algorithm improvement and commercialization development of low-altitude photogrammetry, this new technology is widely used in various fields in foreign countries. This new technology shows a tendency of rapid development in China, especially in the field of surveying and mapping, but in the geological and geotechnical engineering field is at a tentative stage. Based on briefly introducing the new technology of the basic principle and 3D data acquisition method, combined with an example about loess landslide investigation at Heifangtai tableland in Gansu Province, this paper described the application effect of the new technology in the regional landslide investigation and individual landslide investigation. The results showed as follows: ①We could greatly understand the regional spatial distribution of loess landslide in the regional landslide investigation. ②We learned the development characteristics and disaster process of the landslide by means of analyzing pre-sliding and post-sliding low-altitude photogrammetry datum in individual landslide investigation. Thus, UAVs low-altitude photogrammetry technology has broad prospects and research value in the field of geotechnical engineering and geological engineering application.