Abstract: Rapid loss assessment and emergency mapping play an extremely important role in post-earthquake emergency work. Taking the Beijing-Tianjin-Hebei region as an example, this research studied and implemented a novel and practical rapid assessment and mapping technology. Based on off-line data and self-developed software modules, the rapid loss assessment and professional mapping representation could be easily realized. Firstly, the basic geographic data and important earthquake-related data of the Beijing-Tianjin-Hebei region were updated and processed, and the multi-level pre-cached off-line map data was produced based on the principle of LOD (Level of Details) model. Secondly, based on advanced sub-area classification evaluation model and calculation method, the kilometer grid data of earthquake disaster losses under different intensities were generated. Subsequently, an efficient off-line storage management mechanism based on geographical partitions was implemented, for large amounts of off-line map data and pre-assessed loss kilometer grid data. Finally, based on object-oriented programming and graphic image processing technology, the integrated application software for rapid loss assessment and professional mapping representation was designed, developed and implemented. This research has realized the key technologies of the whole chain, and does not rely on any third-party commercial software or service plug-ins. The rapid assessment reports and series of maps can be automatically generated within one minute. The research results have achieved novel practical effectiveness in multiple earthquake events. This research is of great significance for improving the ability of earthquake emergency response.