The construction of ecological civilization in the new era has put forward higher requirements for scientific management of natural resources and modern governance of national land and space. Based on this, the Ministry of Natural Resources has issued the "Overall Plan for the Construction of a Natural Resources Survey and Monitoring System", proposing the concept of "ground substrate" for the first time, and has organized pilot investigations of ground substrate in typical areas. However, there is currently no unified understanding and standard for the three-level classification, survey objects, survey content, and technical system of ground substrate, which seriously restricts the research work of ground substrate investigation. Methods: This study deeply analyzes the scientific connotation of ground substrate, comprehensively considers the data support needs of land agricultural space, land ecological space, and land urban spatial planning, and establishes a layered classification model of ground substrate based on the spatial attribute characteristics of ground substrate. Based on the classification principles of scientificity, uniformity, operability, and applicability, a three-level classification scheme for ground substrate has been proposed, further exploring and clarifying the investigation objects and contents of ground substrate layered classification, and establishing a set of ground substrate investigation and monitoring technology system.Results: ① A spatial stratification model for ground substrate is constructed in the form of "soil layer-sedimentary layer-bedrock layer", which realised the articulation and correspondence between ground substrate layers and substrate types. ② A three-level classification scheme for ground substrate is proposed, which divided the surface substrates into 4 first-level classes, 14 second-level classes and 55 third-level classes. ③ The survey objects and contents of surface substrates are clarified, and the investigation should focus on the distribution of each surface substrate type, physical and chemical properties and geological landscape attributes. ④ A technical system for surface substrate investigation and monitoring has been established, which mainly includes data integration, field investigation, results analysis, simulation and prediction, and other key technical links.Conclusions: In this study, a systematic technical system for ground substrate investigation and monitoring is established through the study of the theoretical model, research object, investigation content, technical methods, and application of ground substrate, which can provide a theoretical basis and reference for further investigation and research of ground substrate.