<p>To study the response mechanisms of slopes under seismic action after different rainfall conditions, a comprehensive analysis was conducted through large-scale shaking table model tests and wave theory. Different instability modes of slopes under seismic conditions after various rainfall events were identified. The changes in modulus and damping caused by the combined effects of rainfall and earthquakes were clarified, determining the mechanism of the acceleration response of slopes. A method for evaluating internal damage in slopes based on the difference between positive and negative energy amplification was established. These findings indicate that the reduction in modulus and damping caused by rainfall leads to a decrease in the natural frequency and an increase in the slope response. The decrease in modulus and increase in damping due to earthquakes result in a lower natural frequency and weakened slope response. The difference between positive and negative energy amplification reflects the internal damage and instability modes of the slope more accurately than the natural frequency and dynamic pore water pressure. The response mechanism of slopes is a theoretical bottleneck in the study of rainfall-induced seismic landslides. The internal damage assessment method is crucial for translating theory into application, with its accuracy and universality being essential.</p>