Ecological suitability analysis is an important method of applying ecological principles to guide rational spatial distribution and regional development for the planning of certain areas. This method has been widely applied in urban and regional ecological planning. However, due to the lack of systematic assessment methodologies, it has not been significantly promoted for spatial siting, ecological planning, or eco-environmental impact assessments of ecologically sensitive areas, such as nature reserve areas and tourism areas. This study proposes the use of an ecological suitability analysis method and a GIS-based mapping approach to develop an eco-tourism project in an ecologically sensitive montane area. We use the Wudangzhao Scenic Area in Inner Mongolia, China, as a case study for analyzing various ecological factors including topography, slope, aspect, soil organic environment, vegetation cover, river hydrology, geology and lithology. These factors reflect the four typical ecologically sensitive elements of erosion prevention, geological disasters prevention, biodiversity protection, and flood control. We first completed the ecological sensitivity assessment and spatial suitability mapping using both single and integrated eco-sensitive factors. We then superimposed the distribution of relevant tourism projects in the research area in relation to the eco-sensitive assessment results in the form of an eco-map. Finally, we suggest specific ecological risk prevention and protective measures for tourism development and spatial planning in the research area. In addition, this method provided a comprehensive overview of all ecologically sensitive characteristics for mountain based tourism projects currently being developed, spatially displaying them through ecological mapping. Therefore, this method contributes to a more effective decision-making process and helps decision makers develop more appropriate regulatory measures to prevent ecological risk. In conclusion, this method provides a scientific and effective technical tool to assess the ecological environmental impact of a project or planned projects in this type of eco-sensitive region.