Abstract: In karst areas, the mountains are bare and the terrain is steep. Once the dangerous rock mass developed instability, it will threaten the lives and properties of the residents. So it is significant to analyze the stability and hazards of the disasters in a timely and accurate manner. Taking the dangerous rock mass of Changchong Group in Heping Community, Songtao County, Guizhou Province as the object, combined with the results of engineering survey, the disaster-generating background of the dangerous rock mass areas, such as topography, geological structure and hydrology, were analyzed, and the development characteristics of the dangerous rock mass were analyzed deeply. The failure mode and influencing factors of dangerous rock mass was demonstrated. On this basis, qualitative and quantitative analysis of the stability of the dangerous rock mass was carried out, and the hazard degree and development trend of the dangerous rock mass are evaluated. The results show that the unique karst landforms, karst features and complex structural planes of the dangerous rock mass developed in karst mountainous areas are the key factors controlling the stability, and rainfall and weathering are the main inducing factors. A preliminary prevention plan has been proposed to provide a reference for subsequent treatment measures.