To address the difficulty of achieving large-scale pressure relief in high-position thick and hard roofs of rockburst-prone working faces, theoretical analysis and field monitoring methods were employed to investigate the mechanism of underground directional long-hole hydraulic fracturing for rockburst prevention and to evaluate its fracturing and control effects. The results indicate that: (1) The underground directional long-hole hydraulic fracturing technique injects fracturing fluid into thick and hard strata to generate fractures, thereby degrading the rock integrity and weakening its capacity to accumulate elastic energy. Meanwhile, the increased fracture density promotes the timely caving of the thick and hard roof in the goaf, which provides supporting effects on the overlying strata and effectively reduces both static and dynamic stresses in the surrounding coal and rock mass. (2) Analysis of borehole pressure, fracturing fluid flow curves, and water discharge during the fracturing process reveals the initiation and propagation of fractures, forming a fracture network and significantly impairing the integrity of the hard roof. (3) After implementing hydraulic fracturing, both the total energy release and frequency of microseismic events are substantially reduced, with a notable decrease in high-energy events. Additionally, the periodic weighting interval and dynamic load coefficient are lowered, while the working resistance during non-periodic weighting remains relatively stable.