To evaluate the seismic risk and loss caused by an earthquake, many earthquake disaster loss assessment softwares have been developed. However, it is difficult to apply one earthquake disaster loss assessment software for all countries due to the different characteristics of seismic, architectural and economic of various countries. China is one of the high-seismicity regions in the world. Thus, it is imperative to develop an earthquake disaster loss assessment software suitable for China. In this paper, a novel framework for plugin-based applications named CEDLES is designed considering the scalability of the software. The features provided by CEDLES to ease the development of extensible applications are described. This framework includes a startup project, a common plugin framework base, a geographic information system plugin framework base, and a plugin manager project. These utilities allow rapid development and integration in which robustness and quality play a fundamental role. A first prototype, Earthquake Risk Prediction and Loss Assessment System (ERPLAS) is designed and implemented. It integrates the plugins of seismic hazard analysis, structural damage analysis, loss assessment, earthquake insurance rate estimation, and benefit–cost analysis of building retrofit, especially for China. ERPLAS is applied to Baqiao District in Xi’an and the estimation results are displayed and debated, which verify the practicality of ERPLAS and the feasibility and facility of CEDLES framework.