Taking the airpowered vehicle decompression device as the research object, the software of Simulink was used to simulate and analyze the energy loss of depressurization process for the throttling decompression and volume decompression device and the Fluent software was applied to the throttling decompression and the twovolume decompression process to conduct the flow field analysis. The analysis results show that the energy loss of the decompression process of throttling decompression device is up to 27% to 59% and is up to 40% under the most frequentlyused conditions of 30 MPa air source pressure and 3 MPa outlet pressure, which is relatively large. Compared with the throttling decompression, the energy loss of volume decompression decreases by 6% to 22% and the energy saving effect is obvious. In addition, the decompression process of throttling decompression device is relatively stable, the output pressure is stable and the throttling effect is obvious. The second stage of the two stage volume decompression device has a more uniform pressure field and velocity field than first stage decompression vessel and the depressurization process is more stable.
