In the process of model design for missile platform test system by modeling technology, the key is to realize the requirements description model design, structure model design and behavior model design of test system.Firstly,the working procedure of test system is analyzed. Then, the model design of test system are carried by UML(unified modeling language) modeling technology. The requirements description model of system is showed by using decomposition of use-case diagram, the structure model of system is built on the analysis of structure system and relevance relation. The behavior model of system is constructed by using sequence diagram. At last, the system structure and arrangement relation of test system are designed based on above-mentioned model design.This design is applied to real developing for misssle platform test system and all test function is realized. The result shows that this modeling method can improves design efficiency, and the test system possesses reuseability and expansibility also based on the practicability.