Abstract: In recent years, geological disasters have occurred frequently in the southwest region, and unmanned aerial vehicle aerial survey technology has obvious advantages in geological disaster detection. This article uses a suspended fixed wing unmanned aerial vehicle as a platform, equipped with a five lens multi-camera to detect and obtain relevant parameters such as debris flow morphology, channels, sources, and zoning in Longmen gully, Liangshan prefecture. The advantages of five lens multi-camera photography and the specific application methods and effects of drone aerial survey technology in debris flow disaster detection are elaborated and discussed. The main understanding is as follows: ① Compared with traditional monocular cameras, five lens multi-camera photography has the advantage of being able to collect data from multiple different angles of vertical and tilt, and the obtained high-definition image data is finely reconstructed to generate orthophoto images. The texture of the 3D model is more comprehensive and has higher resolution.② By using refined reconstruction of orthophoto images and three-dimensional models, a total of 21 sources of landslides, collapses, rock heaps, and dangerous rocks in the debris flow disaster area are interpreted. The net and dynamic reserves of each source material are estimated based on the average thickness and area, providing a data basis for prevention and control design. ③The unmanned aerial vehicle aerial survey technology has advantages such as flexibility, strong emergency response, large survey range, strong traceability, and low flight cost, and has high promotion value and significance in disaster detection.

Key words: multi-camera, hang up the fixed wing, refined reconstruction, debris flow