Accumulation slopes are extensively distributed in the Three Gorges Reservoir area, China. The seasonal variation of reservoir’s water level will induce high-frequency microseisms, which may cause landslides in reservoir banks. The study of the dynamic responses of the slope under earthquakes is the basis of the dynamic stability analysis of the slope. This paper studies the dynamic characteristics and dynamic responses of accumulation slopes under frequent microseisms by shaking table tests. Different moisture contents and dens degrees are treated as the key research contents, and a total of nine slope models have been carried out for experimental studies. The results show that the acceleration responses of the slopes under different working condition exhibit obvious “altitude effect”. The dynamic characteristics refer chiefly to the inherent properties of the model, containing damping ratio and natural frequency, and the change of the latter is more sensitive. With the increasing of water content of the model, the decrease of the natural frequency is less, and the dynamic response shows a linear growth trend. The amplitude of the reduction of the natural frequency decreases with the increase of the dens degree. The results reveal the instability mechanism of the accumulation slopes under frequent microseisms and provide reference for the seismic design of the slope engineering.