Crack propagation caused by vibration of lithosome is a common concern in the fields of subgrade, bridge, vibration construction and earthquake prevention etc. Through combining the home-made inertia loading device with the platform of vibration, we implement 12 groups of vibration loading experiments on similar rock plates with penetrating cracks, observing the propagation and coalescence mechanism. Moreover, we establish the corresponding model in PFC software to analyze mechanism of crack propagation further. The results show that the phase difference of vibration deformation in different regions promotes the crack propagation behavior. The dipping angle between the direction of vibration and the initial propagating direction of notches is a little bit small, within the scope of ±10 degrees. Besides, in the direction of vibration, the notch is easier to propagate; while the couple of notch-middle fracture is prone to coalesce. The frequency of crack collapse shows positively correlative to the crack spacing. With the increase of the dipping angle between the crack inclination angle and the vibration direction, crack propagation becomes more and more difficult; and it’s the most hardly when the crack is perpendicular to the vibration direction. The same as what in static process, the path of crack propagation by vibration is the nearest route, which is consistent with the minimum energy principle.