<p>High-damping cement-based materials can be utilized for constructing earthquake-resistant and vibration isolation concrete structures. Enhancing the damping capacity of cement-based materials significantly has remained a persistent challenge. This study investigated the effects of asphalt emulsion (AE) and rubber fibers (RF) on the damping performance of cement mortar, along with the underlying mechanisms. Results show that the hybrid incorporation of AE and RF significantly enhanced the damping capacity of cement mortar. When modified with 20 wt% AE and 30 vol% RF, cement mortar exhibited a significantly enhanced loss factor, with the mean value increasing by approximately 500%. The study revealed that the synergistic interaction between the viscous damping of asphalt and interfacial friction of rubber fibers significantly enhanced the damping capacity of cement mortar. This work established a novel method for developing high-damping cementitious composites.</p> Graphical Abstract <p></p>