煤层上方复合坚硬顶板结构间的相互作用关系复杂，水力压裂复合顶板的卸压主控层位难以明确。以乌审旗蒙大矿业有限责任公司纳林河二号矿井31104−1工作面为工程背景，综合采用物理相似模拟、理论分析、工程试验的研究方法，分析了复合坚硬顶板破断与能量演化规律，揭示了复合坚硬顶板强矿压形成机理，明确了水力压裂的主控层位。研究结果表明：复合坚硬顶板工作面开采初期，顶板垮落范围集中于低位坚硬顶板，其周期性破断形成工作面周期来压；高位坚硬顶板受下部垮落矸石支撑作用难以充分垮落，工作面推进至一次见方位置时，高位坚硬顶板协同间隔岩层整体切落，工作面产生强矿压现象；采用定向预裂高位坚硬顶板后，工作面覆岩呈现典型的“三带”结构，上方顶板及时破断下沉，工作面见方位置较预裂低位坚硬顶板声发射振铃计数减少了38.36%，微震事件集中分布区能量降低至1 000～2 000 J，且现场实测顶板微震事件总能量、单刀能量及事件数较预裂低位坚硬顶板时分别降低了62.17%，71.92%，56.32%，表明高位坚硬顶板为卸压主控层位，预裂高位坚硬顶板能有效抑制工作面强矿压现象。

The interactions within the composite hard roof structure above coal seams are highly complex, making it challenging to identify the main controlling layers for pressure relief via hydraulic fracturing. Using the 31104-1 working face of the Nalinhe No. 2 Mine at Wushenqi Mengda Mining Co., Ltd. as the engineering background, this study employed physical similarity simulation, theoretical analysis, and engineering tests to investigate the fracture and energy evolution patterns of composite hard roofs. The study revealed the mechanism behind strong mine pressure in composite hard roofs and identified the main controlling layers for hydraulic fracturing. The results showed that during the initial mining phase of the composite hard roof working face, the collapse was concentrated in the lower hard roof, with periodic fractures creating periodic pressure on the working face. The upper hard roof, supported by collapsed gangue below, failed to collapse fully. When the working face advanced to a square position, the upper hard roof and the intervening strata collectively fractured, causing strong mine pressure. After directional pre-splitting of the upper hard roof, the overburden exhibited a typical "three-zone" structure, allowing the upper roof to fracture and sink promptly. At the square position of the working face, the acoustic emission ringing count of the upper roof decreased by 38.36% compared to pre-splitting of the lower hard roof. The energy in the concentrated microseismic event area was reduced to 1000-2000 J, while the total microseismic energy, single-pick energy, and number of events decreased by 62.17%, 71.92%, and 56.32%, respectively, compared to the pre-splitting of the lower hard roof. These findings confirmed that the upper hard roof was the main controlling layer for pressure relief, and pre-splitting the upper hard roof effectively suppressed strong mine pressure on the working face.