Abstract: The classification of Earth Critical Zone is helpful to cognize the spatial distribution and understand the regional differences in the occurrence and evolution of Critical Zone. Besides, it is the basis for the observation and investigation of Critical Zone. To further study the existing large−scale Critical Zone classification, this study constructed a set of small−scale Critical Zone classification frameworks using a multi−level classification method. It made an empirical study of Xixia County in Henan Province by using the map overlay method in GIS. The research results showed a group of multi−level classification frameworks covering classification principles and indexes in the mountainous area, and the Critical Zone of Xixia County was divided into 28 first−level types, 246 second−level types, and 722 third−level types. This classification can improve the overall understanding of earth system science. It also has specific reference significance for scientific research and the comprehensive management of natural resources in the critical zones of the earth at different scales.