Aiming to alleviate the limited test resource situation, oriented graph signal decomposition model is proposed based on the complex signal synthesis method of TSF(Test Signal Framework) in STD(Signal and Test Definition) standard. This paper establishes signal decomposition models for stimulus signal and response signal; which has carried on the detailed analysis and the discussion about this signal model. A series of recursion expressions are put forward to acquire the signal’s (physical characteristics’s of a signal) origination through the deduce process layer by layer. This signal model can be used for any complex signals, and has nothing to do with the specific equipment, while it is completely reusable and portable. When the platform’s independent resources cannot meet the signal requirements, by means of the signal model the combination of the independent resources can be used to achieve the automatic allocation of the stimulus /measurement resources. The signal model also provides an implementation approach that is used to the interchanges between synthetic instruments and the instrument combinations as well as the interchanges between the instrumens combinations. So that it can save the system resources and reduce the cost greatly.