This paper conducts a large-scale shaking table model test of an isolated mountain on a scale of 1∶10. The model is constructed using soil and has a height of 1.8 m, length of 4.4 m, width of 4.4 m, and four slope angles of 30°, 45°, 50°, and 60°. A series of tests are performed with different input seismic wave types, amplitudes, and frequencies. Dynamic response characteristics of isolated mountains under earthquakes are discussed, as well as the influence of ground motion parameters. Conclusions obtained are as follows: (1) the topographic amplification effect of peak accelerations in the vertical direction and free-surface direction gradually increases with an increase in the slope angle: when the slope angle is 45°, the amplification effect of peak accelerations suddenly increases but decelerates when the angle is 50°. However, there is minimal change in the amplification effect of peak acceleration along the slope strike direction with an increase in the slope angle. (2) There is a gradual reduction in the topographic amplification effect of peak accelerations in the vertical direction, free-surface direction, and slope strike direction with an increase in the peak ground accelerations of the input wave, revealing an intensity saturation phenomenon. These results reveal the mechanism of slope instability under earthquakes and can be used as a reference for seismic design during slope engineering.