The paper presents systematical investigation and assessment methods for a large-scale landslide. The aim of the investigation methods is to understand the regional environment, protected targets, and characteristics of the sliding mass. The purpose of the assessment methods is to estimate the slope stability and influence zone under different scenarios. Taking Xinzhuang village as an example, the paper illustrates how to judge the potential sliding mass, build a hydrogeological conceptual model, and estimate the slope stability and influence zone of a potential large-scale landslide near Xinzhuang. This paper can serve as a reference for other villages with disaster prevention strategies for dealing with large-scale landslides.