To analyze the micromechanical response of asphalt mixture during field compaction, a 3D compaction model was developed based on particle flow code in 3-dimensions (PFC3D) by considering the asphalt pavement properties and compaction temperature. The Burger’s model parameters were obtained by dynamic modulus test with time-temperature superposition (TTS) principle, and were used to describe the contact behavior between aggregate and asphalt. Micromechanical characteristics, such as aggregate migration and motion, evolution of contact force and energy were investigated during field compaction. Results showed that asphalt pavement displacement displayed non-continuity and asymmetry. Meanwhile, aggregate motion and stress were concerned with the load position and orientation of compaction load. The laws of aggregate motion in compacted areas were different from the non-compacted areas, and the analogous whirlpool condition was formed in the transitional zone of the compacted and non-compacted areas. Additionally, the compacted areas were mainly dominated by contact pressure. The work of external force and strain energy increased quickly at the initial stage of compaction, and gradually decreased at the later stage. Due to the unstabilized compaction stress that resulted in a faster speed, the kinetic energy developed abnormally. However, once the compaction model entered a stable stage, the kinetic energy decreased. These results agree with those of preliminary research. It is reasonable to conduct a survey of the microscopic behavior of asphalt mixture with discrete element method (DEM). The DEM can be employed to investigate micromechanical characteristics of asphalt mixture during filed compaction.