The self-oscillation device has many advantages and is therefore suggested to be used in the pipeline supercharger. Simulation and analysis on the pressure-increasing effect of the pipeline supercharging caused by self-oscillation cavity were carried out by finite element method. The cavity structure of self-oscillation device was designed using the fluid network theory, natural frequency calculation, resonance conditions and Large Eddy Simulation Theory. A series of flow field distribution chart of the self-oscillation cavity were obtained. Results validate that the self-oscillation device is effective to increase the pressure of the pipeline supercharger. The relation curves of pressure-increasing effect with different structure parameters of the cavity were further analyzed. Previous experimental results are accordant with the present simulation results. It shows that the numerical analyses are reliable.