Abstract: To achieve spatial data integration from multiple data sources, a query system framework of multiple spatial database is proposed and its working principle is introduced. According to the spatial object relation model based on multiple data sources, to meet the requirement for the spatial database query, a data query algorithm including query decomposition and filtering is proposed for the data source in which spatial data and non-spatial data are managed separately, and several methods for query optimization in spatial data query are analyzed. A spatial database query technology for multiple data source is developed.