Abstract: In this paper, the load reduction and energy dissipation buffer were studied for pipelines which are buried in shallow depth or impacted by rockfall. Then, the energy dissipation isolation effects of the EPS cushion with different thicknesses and initial densities were simulated by ANSYS/LS-DYNA. It is shown that under the impact load of rockfall, EPS cushion has a significant effect on the energy dissipation isolation of impact energy. It is indicated by comparing the effective stress-time curve of the pipeline without EPS cushion and that with EPS cushion that the energy dissipation isolation effect of EPS cushion can reach about 5-7 times under the same conditions. And the following results were obtained by conducting further study on EPS cushion. First, lower-density EPS cushion can effectively reduce the peak effective stress of buried pipelines, and the application of low density EPS cushion in practical engineering is a superior choice. Second, the thickness of the EPS cushion is not in a simple proportional relationship with the energy dissipation isolation effect. As the thickness increases, the peak effective stress of the buried pipeline decreases firstly and then increases. Third, the thickness of the EPS cushion on buried pipelines shall be determined based on the actual soil depth of the pipeline and the modulus of the flexible filler.