To gain an in-depth understanding of the mechanical behavior of existing asphalt pavement structures affected by reflective cracks, a macro-meso coupled model of a typical semi-rigid base asphalt pavement was established based on a continuum-discrete coupling method. By incorporating reflective cracks with varying vertical lengths, the stress transfer paths, mesoscopic particle stress states, and displacement evolution of the pavement structure were analyzed. The results indicate that the coarse aggregate skeleton and the surrounding mortar collectively bear more than 75% of the traffic load, forming a critical load transfer system, and that a significant linear correlation exists between the vertical stress and effective stress of particles along the primary stress transfer path. The vertical propagation of reflective cracks significantly disrupts the original stress diffusion path, leading to force chain concentration, increased contact forces, and a substantial rise in effective stress. When the crack extends to the pavement surface, the displacement field of particles near the crack changes significantly, with enlarged displacement magnitudes, resulting in a pronounced degradation of fatigue performance across all structural layers.