Abstract: In order to study the stability of the dump slope under vibration and the law of slip initiation, an analogue simulation test was carried out on the dumping site in the Hequ open-pit coal mine by using the self-developed block-distributed bulk slope stability simulation test device.The stability status of slope and the startup mode of landslide under different block compositions and vibration frequencies were compared and analyzed.The model is bounded by a first step flat with an elevation of +1 004.0 m.The average particle size is 1.05 mm above +1 004.0 m and 9.26 mm below +1 004.0 m.The vibration frequency increases step by step during the test and the increment is 5 Hz.The test ends with a starting frequency of 10 Hz up to 40 Hz.It is used to simulate the difference of vibration frequency and different vibration intensity during the propagation of seismic waves on site.The accelerometer is used to collect the acceleration data of the test bench in the three directions of x, y and z at each stage of the test and plot the acceleration time history curve and fit it.The test results show that at 10-20 Hz, the dump slope can be basically stable.The vibration frequency of 20 Hz makes the second step first appear as a large-scale slope block slip.The model is in a state of continuous destruction when 20-40 Hz.It shows that the vibration frequency of 20 Hz is the limit vibration frequency for the slope of the dumping site.In the low frequency and high amplitude state, the particle motion of the block larger than 5 mm is mainly rolling.In the state of high frequency and low amplitude, the movement of large-scale materials on the slope mainly relies on the sliding friction of small blocks to drive and push, and the sliding mode of the material on the surface of the slope is mainly sliding.By comparing the test results, the appropriate block degree can improve the stability of the bulk slope of the dumping site and increase the resistance of the bulk slope to vibration.This provides a basis for the open pit mine to use the mixing of coarse and fine materials in the dumping work.The proportion of the best coarse and fine materials for maintaining the slope of the dump site can be studied in succession.