When new buildings are built on the high fill slope in mountain area, it is necessary to take the overall stability of the slope as the premise, and select a suitable and reliable foundation form at the same time. Based on a practical case of high fill slope, according to the characteristics of the proposed building and slope, different slope stability analysis methods are used to calculate and analyze the slope in the investigation. The proposed building plans to adopt large-diameter rock socketed pile foundation combined with slope protection structure to jointly ensure the safety and stability of the building.