<p>Landslides induced by earthquakes and groundwater are more complex than those induced by earthquakes or groundwater alone. We investigated the dynamic response of slopes with different heights and angles to the combined action of earthquakes and groundwater. The findings revealed that as the slope height increased, the horizontal acceleration amplification factor (AAF) and vertical acceleration amplification factor (VAF) did not rise continuously; instead, they initially increased and then decreased. In line with general observations, the excess pore pressure ratio within the slope gradually declined. The distribution of the AAF was influenced primarily by the slope angle. With increasing frequency, the slope’s AAF showed an initial rise followed by a decline. Under the action of pulse-like ground motions (PLGMs), the AAF and VAF of the slope were comparable to and greater than those of the original record, whereas for the residual record, the ratio of excess pore pressure was similar to and exceeded those of the original record, but was less than that under pulse action. This study explored the dynamic performance of slopes under the joint impacts of seismic activity and groundwater. It compared the ways in which groundwater affects the seismic dynamic response of slopes. Additionally, it studied and contrasted the disparities in the failure mechanisms of seismic slopes in the presence and absence of groundwater. The findings are conducive to a more profound comprehension of the dynamic responses and stabilities of slopes under the combined action of earthquakes and groundwater.</p>