Abstract:Tai'an city is located in the central mountainous area in Shandong province. Mountains and hills are widely distributed, and geological disasters, such as landslide, debris flow and karst collapse are well developed . In the past, many rounds of geological disaster investigation and verification have been carried out in Tai'an city. In this study, based on a new round of geological disaster risk survey with the scale of 1∶50000, analysis and extraction of high precision DEM, structure, engineering geology, and hydrogeology, rainfall and vegetation data based on spatial analysis function of ArcGIS platform, evaluation of susceptibility of debris flow and karst collapse by information method and hierarchical analysis, taking rainfall as a risk assessment factor, considering the population and economic selection of land types as vulnerability factors for risk regionalization, geological disaster risks are divided into high level, medium level and low level. It will provide a basis for effective prevention and control of natural disasters, territorial spatial planning and sustainable economic and social development.