A large-scale shaking table model test of a slope with a height of 1.8 m, length of 4.4 m, and width of 4.4 m was introduced. The materials are made of blanc fixe, river sand, gypsum, clay, and water in different ratios. The slope comprises 30°, 45°, 50°, and 60° inclined surfaces. A series of tests were performed for different seismic waves, amplitudes, and frequencies. The results indicate that the local coordinate system is more adequate than the whole coordinate system when conducting research on the dynamic problems of the slope. Thus, we should use the airport surface direction L, the strike direction M, and the vertical direction N. The amplifications of the peak accelerations gradually increase with the increase of slope angles, and there are two inflection points at 45° and 50°. However, the amplification along the slope strike direction is consistent. The amplifications of the accelerations in different directions gradually reduce with the increase of the peak ground acceleration of the input wave, which is an intensity saturation phenomenon. Simultaneously, there are predominant peak values in the airport surface direction L; however, there are no predominant peak values in the strike direction M and in the vertical direction N. Therefore, the results reveal the mechanism of slope instability during an earthquake and provide seismic design references for slope engineering.