Abstract: The water-power erosion is controlled by several geological factors in Shaanxi Province, the Inner Mongolia Autonomous Region and Shaanxi Province. On basis of analysis of geological factors, dominating factors are selected including soil type, vegetation, landform, ravine, topography slope, soil-using type, mine area, rainfall intensity, water and soil conservation, and wind intensity. The thematic layer of every dominating factor is constructed by GIS and RS interpretation, and weight coefficient of every dominating factor is determined by AHP method. With application of coupling GIS,RS,AHP model, thematic layers are superimposed according to the respective weight and subarea threshold is taken by frequency histogram, finally, coupling model with multi-source geology information is built to assess danger degree of water-power erosion and subarea assessment is carried based on danger degree. The construction of coupling model has laid a solid theory foundation for subarea assessment and forecast and makes it more scientific, rational and quantitative.