Abstract: Based on international and domestic rockfall risk assessment practice, this paper has put forward the risk assessment method for single rockfall geo-disaster taking an example of rockfall in Danba County, Sichuan, China. Furthermore, reliance analysis program of dangerous rock stability is compiled based on basic principle of Monte-Carlo, and probability of instabilities under different conditions are calculated. At the same time, the author takes into account the impact of ground buildings which can block the falling rocks, motion trajectories of falling rocks are simulated in using professional software, moreover, in accordance with the topography of study area, the influence scope is delineated also. Vulnerability research of the disaster-bearing bodies and assets hawe been developed according to the field investigation and local social economic data. In light of above probability and vulnerability analysis, economic loss within the influenced area under different conditions and rockfall risk has been undertaken. These results can provid scientific basis for civil construction and planning in the influenced area to avoid and reduce geo-hazards effectively.