To research the effect of vertical earthquakes on rectangular underground structures in inclined liquefied foundations, and explore the seismic response characteristics of the structure with bidirectional earthquake, the finite element-finite difference coupled numerical method is used. The results revealed that the vertical earthquake will increase the degree of soil liquefaction in the vicinity of the structure and the dynamic response of the structure. The influence is related to the type and amplitude of the seismic wave. The displacement of the subway station will increase gradually as the compactness of the sand decreases or the angle of inclination of the ground increases. The lateral displacement of the subway station mainly occurs during the earthquake, and the vertical displacement mainly occurs after the earthquake. In addition, in the inclined site, the vertical displacement and internal force of the left and right sides of the underground structure and the excess pore water pressure ratio of the soil are not symmetrically distributed along the central column, and the closer to the bottom at the slope, the larger the settlements of the structure produce to make the whole structure rotate. The study can provide some seismic strengthening suggestions for underground structures in the inclined liquefiable site with bidirectional earthquakes. The seismic design of underground structures also needs to take into account the effects of the structure rotation during an earthquake in the inclined liquefiable site.
