<p>The micro-damage of archaeological wood begins with lower axial stress compared to modern wood, but the mechanisms of micro-damage to its cell wall layer still needs to be discussed. This study investigates the micro-damage mechanisms of archaeological wood under axial stress, using a multilayered finite element model to predict damage initiation sites. Scanning electron microscopy (SEM) validated these predictions, revealing damage initiation and evolution. The results showed that both archaeological and modern wood (fir, pine, and camphorwood) exhibited equivalent stress concentrations at the S_1-2 transition under axial compression. Micro-damage primarily initiated in the fillet regions of the S_1-2 transition, marked by interfacial debonding and microfibril-bundle bridging during crack propagation. This research offers valuable micromechanical insights into the micro-damage mechanisms of archaeological wood, providing a scientific foundation for the conservation and restoration of wooden cultural relics and structural health monitoring of in-service wood.</p><p></p>