Abstract: Software design pattern is the use of object-oriented technology to solve certain problems under a particular condition, which is the software design process for problems of a specific environment. It can share the successful experience and solutions, reduce the complexity of problem solving and improve the design of the modular. At the same time, meteorological software construction has entered a rapid developing stage, requiring higher system reliability and reusability, thus it's particularly important to analyze systems and the design of pattern. If the past development practices are considered reasonably and professional software development model is applied properly in agrometeorology software development process, the program can be more logical with reasonable structure and high code reusability.The analysis on the development and changes in agrometeorology service needs imply that the existing agro-meteorological service systems are non-unified and non-standard in architecture, data management and product production. A model based, factory method supplemented design pattern is proposed in order to meet the needs. However, there are more than one system design patterns, so similar applications may also have a variety of useful patterns. Choosing what kind of design patterns depends on the development of the information technology, the change of business needs and the result of application. On the primary technologies with this pattern are discussed, such as the overall framework of the mode model, data control model, data service model, data encapsulation component model, plug-in module reuse management model and professional development. Two samples, one evaluation system based on ArcMap platform and the other based on Oracle database are analyzed to illustrate the dynamic library data component plug-in technology, packaging technology, and their application.With the support of standard database, framework development technology and the development of GIS component, the plug-in professional module technology has been basically achieved and proved effective in operation. In the project which is called National Agrometeorological Disasters Service and Security System, this technology is fully applied. But more complex and professional module design requires further research to meet the changing operation requiements.