Abstract: The morphology of three liquid columns impacted by a plane shock is investigated by using the space-time conservation element and solution element method. The evolution of the shock system and interface deformation of the three liquid columns are demonstrated. The flow inside the channels between the liquid columns enhance the interaction between the shock waves. It leads to uneven pressure distributions on the windward surface of the downstream liquid column. And it also causes its windward surface to evolve from a curved surface to a flat one within a short period of time. The windward pole displacement and width of the downstream liquid column are measured. The narrowing trend of the channel between the two upstream liquid columns weakens the impact of the air flow on the windward pole of the downstream liquid column. It also reduces the velocity of the windward pole displacement. The dimensionless widths, heights, and center-of-mass displacements of the entire three liquid columns are measured. It is found that the width of the second channel plays a key role in the interaction between the airflow and the liquid interface. As the width of the second channel decreases, the ability of the airflow to interact with the interface strengthens and the deformation rate of the dent at the back of the upstream liquid column accelerates. The tip on the first channel side disappears. Then, the turning point of the dimensionless width of the three liquid columns from decreasing to increasing occurs earlier. Additionally, the dimensionless centroid displacement slows down at a later stage. In the case of large second channel width, the upstream liquid column maintains a symmetric shape. However, in the case of small second channel width, the upstream liquid column shows significant asymmetry at the wave system evolution stage and no longer exhibits symmetric features.