<p>Tetrahedral-cluster abrasive belts are increasingly utilized in precision grinding of titanium alloys due to their superior self-sharpening capability and prolonged service life. This study systematically investigates the lifecycle degradation mechanisms of such belts during the grinding of TC4 titanium alloy, with a focus on the transitions in abrasive behavior and the resulting surface responses. Through full lifecycle grinding experiments, we characterize the evolution of wear morphology, material removal rates, surface roughness, and process signals across three distinct wear phases: initial transient fluctuation, middle-stage exponential decay, and terminal rapid deterioration. The results reveal that initial wear is dominated by macro-fracture of abrasive clusters, leading to high surface roughness and unstable material removal. Middle-stage wear transitions to microcrystalline cutting, resulting in stable surface quality and consistent material removal. Terminal wear is marked by severe grain spalling and frictional heating, causing a complete loss of grinding capability and deterioration of surface integrity. These findings provide a comprehensive understanding of the multiscale wear mechanisms and offer a theoretical basis for predictive monitoring and optimization of grinding processes using structured abrasive belts.</p>