Overhanging rock aggregates are the physical basis to trigger large-scale collapse disaster, and it is a major scientific problem in geological disaster monitoring and early warning for overhanging rock aggregates to rupture. This paper established an experimental model to explore exciting vibration of overhanging rock aggregate, and carried out an experiment, which produced about 270 000 pieces of excitation signal data characterized by acceleration. Experiments show that interface integrity between overhanging rock attenuates the transfer efficiency of excitation signal in the aggregates. Meanwhile, main excitation and secondary excitation consist in exciting signal. In the experiment, main excitation appears from 20 ms to 50 ms, and secondary excitation occurs at the 90~100 ms. Especially, dispersivity of secondary excitation is negatively correlated with interface integrity on overhanging rock. The failure of overhanging rock in overhanging rock aggregate is random, however, exciting action is inevitable in aggregate when overhanging rock failure occurs. Model test implies that the main excitation may be the excitation factor of the large-scale and super-large-scale collapse disaster, while the secondary excitation is the pacemaker to trigger avalanche failure of overhanging rock aggregate. The research results provide scientific reference for further study on failure mechanism of overhanging rock aggregate.