Abstract: During the flight, the transportation pipelines of the spacecraft, which convey the fuel from the store tank to the engine, are subject to composite environmental loads, such as the low temperature, the internal pressure and the vibration. So the structural fatigue analysis and the dynamics identification of the pipelines are very important in the development course. This paper analyzes the responses of the transportation pipeline system in the vibration test under three medium load conditions, i.e. the state of the non-load, the internal pressure and the combined load of low temperature -internal pressure -additional mass, and the impacts of the medium load applied to the thin-wall and light weight pipelines. The conclusion may be useful for the ground validation test of spacecraft transportation pipelines.