The study of the suitability of prehistoric human settlements (SPHE) can help us reproduce the process and characteristics of prehistoric human settlements, and is an important entry point for exploring the relationship between prehistoric humans and land. In this study, we discuss the definition, compositional structure, evolutionary mechanism, and spatiotemporal representation of the suitability of prehistoric human settlements, and propose its main research lines and possible research contents. We believe that the suitability of prehistoric human settlement environments refers to the ability and process of natural and social environmental conditions to meet the needs of human survival within a certain spatial range centered on the settlement of prehistoric humans. Additionally, with the temporal and spatial evolution of humans, society, and nature, it shows local consistency and global gradual and continuous change characteristics, and the human settlement environment has a suitability hierarchy of natural original, livelihood, and living spaces nested step by step. We believe that we can adopt the main research line of prehistoric human settlement suitability system construction to conduct extensive experiments and demonstrations on the theoretical construction, the evolution of the environment and living process, the relationship and evaluation of prehistoric human needs, the transformation of the living environment, living adaptation theories and models, and value and limitation verification. Thus, a complete research system can be formed to explore the evolution of the prehistoric human–land relationship.