The invention discloses a spatial database synthesis method in land utilization information multi-scale expression; a spatial database in the land utilization information multi-scale expression is synthetically divided into two steps: semantics synthesis and graphics synthesis, wherein, the process of the semantics synthesis is synthesis constraint based on a thematic data base, under the control and guidance of knowledge inference, the geographic characteristics of land features in the database is judged, comprising the steps of identifying the spatial relation of land feature types, land feature grades, spatial position and other land features and determining the importance of the land features, therefore, the process is structural identification. The graphics synthesis is the synthesis of point features, line features and surface features under the guidance of cartography theory. The synthesis model based on the database is built, the standardization of database synthesis is realized, and the disadvantages that the traditional cartography synthesis only concerns graphics synthesis and neglects special semantics synthesis are overcome.