Abstract: There are many geotechnical engineering problems in the formation of excavation and filling sites in collapsible loess area, and engineering accidents will occur if the problems are not effectively identified and prevented. In order to avoid the occurrence of related engineering accidents and ensure the safety of engineering construction, the key geotechnical engineering problems and treatment measures based on engineering practice were analyzed. The safety of slope and excavation, the prevention and control of surface water and groundwater, and foundation deformation are the main geotechnical engineering problems. The wetting deformation of filling body is the key and difficult point. Waterproof and drainage are the main measure to avoid engineering problems. The buildings near the top of the slope should be embedded, and the uneven earth pressure on the foundation (basement) should be considered for the buildings near the bottom of the slope. It is easy to form saturated soil on both sides of the excavation and filling interface and around the spring point. The main seepage channels of groundwater are in strongly weathered rock and strongly permeable rock with monoclinic structure. Slope treatment, waterproof and drainage, foundation treatment, excavation engineering, building embedment should be considered systematically.