In order to explore the stress and strain relation in the pavement layers under traffic load from a mesostructural perspective, the singlescale discrete element model of asphalt pavement structure was built using discrete element method(DEM). The stress and strain at the bottom of the asphalt concrete layer under vertical load were calculated. The validation of discrete element model of asphalt pavement structure was conducted by the comparison of discrete element prediction with the results from the classical program. The distribution and volumetric fraction of coarse aggregate, asphalt mastic and air voids were taken into consideration at the bottom of the asphalt layer in the validated discrete element model to build the multiscale structure of asphalt concrete pavement. The tensile stress and strain in asphalt mastics and interface between aggregate and mastic were obtained and compared with the results from the singlescale model. Results show that the stress and strain in multiscale structure is heterogeneous distribution. The tensile stress at the interface between aggregate and mastic is much higher than that in mastic. The ratio of stress at interfaces to the stress in mastics increases as the mastic stiffness decreases. The pavement design based on singlescale model may underestimate the tensile stress at interface between aggregate and mastic and overestimate the tensile stress in mastic.