Abstract: Based on the analysis of Chinese national farmland classification technical route and systematic requirements and physical model, the paper combines the user requirements and the systematic information stream with logic confusion ways. Furthermore, the article divides the national level database system requirements into three layers: database application, database management and infrastructural data integration. Then the framework of system was composed of four levels: user access level, public database service platform level, database organization level and database establishment. Four key technologies were also discussed such as information collection and integration, matadata database model, inter-provincial classification grades adjustment model and database update technology, and Decision Support System model based on fuzzy mathematics.