The telemetry data processing system is used for the tests of weapon system, and the telemetry data processing of slow variation parameters and fast variation parameters is completed in the meantime. In order to overcome the drawbacks of the old system and build a highly efficient and reliable system software, the object oriented analysis and the design method are used in this paper．On the basis of detailed analysis of system function and requirement, the use case model, the static structure model and dynamic behavior model are established using UML’s standard and general characters in modeling expression. The function structures of the system are demonstrated by visual graphical interfaces. The models describe the information exchange between system objects and system for dynamic events processing, which makes the system software design and development work more standardized and reasonable, also shortens the software development cycle. Finally, the system construction is completed and applied to the actual task successfully, and the applications prove the feasibility and validity of these models．