In order to investigate the seismic effect analysis of High-Filled Cuter Cover Tunnel based on equal load reduction rate and considering the timeliness of filling, three load-reducing materials, namely, EPS board, low-pressure solid soil and rubber granular improved soil, are selected, and the effects of the differences in load-reducing materials on the soil pressure around the caves and the safety of the lining are analyzed under the effect of earthquakes, using a combination of experiments and numerical simulations. The results show that: under seismic action, the average vertical dynamic soil pressure on the left side of the cave roof is 1.12~1.05~1.02 times of the static loaded soil pressure, and the dynamic soil pressure on the right side is 1.02~1.01~1 times of that on the left side; the horizontal dynamic soil pressure on the left and right sides of the cave shows a trend of "this is the opposite of the other", and the average horizontal dynamic soil pressure on the left side of the cave is 0.5~2 times of that on the right side. The average horizontal dynamic soil pressure on the left side (right side) of the hole is 0.63~0.88~1.03 times (1.95~1.32~1.08 times) of the static load soil pressure. The distribution of structural safety coefficient tends to be symmetrical from asymmetric in order, and the smallest part of the safety coefficient is transferred from the arch top to the right side wall. When seismic design is carried out in High-Filled Cuter Cover Tunnel, attention should be paid to the safety performance of the lining structure arch top and right side wall.