In order to make full use of the powerful display and analysis ability of meteorological data in the MICAPS4 system, a application system for disastrous weather case database in Shanxi Province is designed under the framework of the .Net Framework 4.5, using the C# programming language, the MySQL database, and the secondary development interface provided by MICAPS4. The system achieves such functions as the management of historical case database, the retrieval and analysis of historical cases and cases similar to the model forecasting data, and the training and exam simulation of historical cases. At present, the system has been applied to forecasting operation. The system is not only scalable and easy to be localized, but also practical, so it has high application value. This paper describes the design, development, functions, and realization of the system in detail.