Based on the requirements of the “Realistic 3D China” initiative and the construction of a new fundamental surveying and mapping system, this paper clarifies the connotation and components of terrain-level geographic entity conversion by integrating the characteristics of Guizhou’s multi-source heterogeneous geographic information data. Furthermore, it systematically outlines the conversion production process and technical methods, providing a valuable reference for geographic entity conversion in Guizhou Province and other complex terrain regions across Southwest China.