Abstract: Zelongnong Gully is located on the right bank of YarlungZangbo River in Milin County, Nyingchi, Tibet, which belongs to the post-earthquake affected area. Due to the steep terrain, abundant material sources and abundant water sources in the gully, the high-level geological disasters occurred frequently in the gully during 1950—2020, and the villages and bridges in the gully suffered serious threats for a long time. According to the field investigation and UAV aerial photography, combined with multi-stage remote sensing images and InSAR data, this paper interprets the types and quantity of high-risk sources in the formation area, as well as the movement and accumulation characteristics of loose deposits in the circulation area and accumulation area of Zelongnong Gully. The results show that at present, there are a large amount of glacial moraines of multistage and multi-period accumulation in the interface area between the formation area and the circulation area, and the fluidity is strong. The regional geological conditions, seismicity, meteorology and hydrology and other factors provide unstable source structure, good free space condition and storage platform, sufficient potential energy conversion condition and hydrodynamic condition for the occurrence of Zelongnong high-level chain geological disaster. The formation and evolution process of the high-level geological disaster chain in Zelongnong gully is summarized as follows: high ice collapse (rock collapse) - debris flow - mud-rock flow - blocking river and barrier dam (lake) - flood disaster, which has high vulnerability and high risk in the long term. In the later period, the monitoring, early warning and risk prevention and control of high-level geological disaster chain in Zelongnong Gully should be strengthened.