Hindered phenol AO-80/polyacrylate rubber damping hybrids are novel damping materials. They were fabricated to study the influence of the content of the hindered phenol AO-80 on their damping performance and mechanical properties. Molecule dynamics (MD) simulation, a molecular-level method, was applied to elucidate the microstructure and mechanism of the hybrids through the radial distribution function (RDF), fractional free volume (FFV), and cohesive energy density (CED). MD simulation results revealed that three types of hydrogen bonds, namely, type A (AO-80)-OH center dot center dot center dot O=C-(ACM), type B (AO-80)-OH center dot center dot center dot O=C-(AO-80), and type C (AO-80)-OH center dot center dot center dot OH-(AO-80), were formed in the AO-80/ACM hybrids. Meanwhile, the experimental results using positron annihilation lifetime spectrometry (PALS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and dynamic mechanical thermal analysis (DMTA) found that the introduction of AO-80 could remarkably improve the damping properties of the hybrids, including an increase in the glass transition temperature (T (g)) as well as the loss factor (tan delta).