Computer simulation methods such as quantum chemistry calculation, molecular mechanics, molecular dynamics and dissipative particle dynamics were introduced. Its applications on different situations of interactions which exist in explosive dimer, trimer and crystal, between different explosive molecules, explosive molecule and the additives, different additives and on the interface were summarized. Future development of computer simulation for intermolecular interactions in composite explosive was prospected, the improvement of accuracy and speed, the modification and development of molecular forcefield, and the actualization of multi-scale simulation are considered as the hotspots of the research.