Abstract: In order to study the interaction mechanism of explosive cracks between adjacent holes under explosive load, a new digital laser dynamic caustic line experiment system was used to study the mechanism of explosive cracks growing each other under different spacing and different charge structure by changing the spacing of holes and adjusting the structure of charge package. The results show that the explosive cracks in the two holes are randomly distributed in the case of the ordinary drug package,and the explosive cracks expand independently in the early stage when the slit drug package interacts with the ordinary drug package,and attract each other as a free surface in the later stage. When the two holes are interacted with slit charge,the explosion-induced cracks are distributed in a "straight line" in the direction of the central axis of the holes. When the spacing is large,the crack distribution in the direction of the central axis of the gun hole is "hand-in-hand". With the increase of hole spacing,the energy loss of crack encounter is larger,the peak value of dynamic stress intensity factor and crack velocity are smaller,and the amplitude is lower. The area of crushing zone formed around the hole and the length of secondary crack are smaller,and the fractal dimension is smaller.