<p>Rockbursts pose a critical threat to the safe and efficient construction in deep tunnels. Rockburst warning and mitigation technologies based on microseismic (MS) monitoring are vital for rockburst tunnels. However, conventional MS parameter calculation methods, rooted in seismology, may not be optimal for all fracture mechanisms in deep hard rock tunnels, particularly tensile failures. This study established a mechanism-based method for calculating MS source parameters, distinguishing between tensile failure and shear failure. Afterwards, the fracture mechanisms and temporal evolution of multiple MS parameters across different rockburst types were investigated. The results demonstrate the superior fitting performance and magnitude inversion of our method for microseismic events. Analysis reveals that the proportion of tensile fractures gradually decreases from strain rockbursts to strain-structure slip rockbursts to fault rockbursts, although it still exceeds 60% in fault rockbursts, indicating tensile failure dominates excavation-induced fractures in deep hard rock. Energy release in strain rockbursts occurs mainly via tensile failure, whereas fault rockbursts release energy predominantly through shear failure. Strain-structure slip rockbursts exhibit hybrid characteristics. Critically, more than 97% of the accumulated energy was released abruptly during the studied fault rockburst, demonstrating significant suddenness and explaining why conventional energy-based warning methods underestimate its intensity. A targeted warning strategy for fault rockbursts should therefore integrate energy release, inelastic deformation, and stress adjustment. This study provides a key foundation for the advanced quantitative warning of fault rockbursts.</p>