Abstract: In the process of mining, the elastic energy release of hard roof breaking is easy to induce impact disaster. In particular, there are multi-layer hard roofs above the coal seams in the Shaanxi-Inner Mongolia region. The mechanism of roof structure instability induced by the combined action is complex, which leads to the difficulty of controlling the impact disaster in the stope and threatens the safety of mine production. Based on the engineering background of rock burst prevention and control under the condition of composite hard roof in 31104 working face of Nalinhe No.2 Mine, the fracture mechanics model of the composite hard roof was constructed, the structural stability characteristics and mine pressure behavior of composite hard roof were analyzed, and the fracture and pre-splitting weakening characteristics of composite hard roof were revealed by means of theoretical analysis, physical similarity simulation experiment and field monitoring. The results show that in the early stage of mining, the lower hard roof mainly forms the cantilever beam structure, and its periodic breaking forms the periodic pressure of the working face. The average weighting step is 21.2 m. The upper hard roof is supported by the lower caving gangue, which is easy to form a masonry beam structure. When advancing to the first square position, the rotary instability of the upper masonry beam cooperates with the cutting instability of the lower cantilever beam. The coordinated movement of the upper and lower hard roofs leads to the increase of the moment of inertia, and the rotation energy of the broken rock mass increases rapidly, resulting in strong mine pressure in the goaf. After the pre-splitting of the composite hard roof, a large number of cracks are formed inside, and the lower hard roof can collapse fully and timely. The periodic pressure step of the working face is reduced, and the average pressure step is 15.2 m, which is 28.3% lower than that before pre-splitting. The supporting and restraining effect of the lower hard roof caving gangue on the upper hard roof is weakened, the rotation amplitude and energy of the broken rock block are reduced, and the synergistic failure effect of the upper and lower hard roofs is effectively suppressed. When advancing to the first square position, the total energy of microseismic events and the peak value of advanced stress of coal body after pre-splitting of composite hard roof are 62.5% and 31.5% lower than those before pre-splitting, respectively. The field engineering test shows that after the pre-splitting of the composite hard roof, the total energy, frequency and single knife energy of roof microseismic events are reduced by 62.17%, 56.32% and 71.92% respectively, and the average periodic pressure step distance, pressure range, peak value before pressure and peak value during pressure decreased by 53.5%, 38.03%, 8.63% and 5.96% respectively, indicating that directional water pressure pre-splitting can effectively suppress the strong rock pressure phenomenon at the square position of the working face. The research results can provide useful reference for the prevention and control of impact disaster of composite hard roof.