Abstract: High and steep rock slopes, a common outcome of mountainous engineering and excavation, are prone to frequent and damaging rockfalls. Accurately pinpointing rockfall sources is crucial for mitigating these hazards. While UAV photogrammetry has emerged as a primary investigative tool, its ability to model complex slope features such as cavities and fissures in three dimensions remains inadequate. Moreover, a lack of straightforward rapid identification indices hampers the precise location of rockfall sources. This paper introduces a multi-perspective 3D UAV flight path planning method for high and steep rock slopes, enabling comprehensive and detailed 3D modeling. Building on this, a rapid identification technique for rockfall sources was developed, featuring an index system based on suspended surfaces, surface roughness, and fissure index, along with extraction methods and swift identification protocols. Field applications demonstrated that these techniques significantly enhanced the precision of three-dimensional modeling for high and steep rock slopes and facilitated the rapid, simple, and efficient identification of rockfall sources, holding substantial value for broader application.