epsilon-2,4,6,8,10,12-Hexanitr 0-2,4,6,8,1 0,12-h exaazais owurtzitane (CL-20) is currently the most powerful explosive commercially available. Nevertheless, the early decay events of shocked epsilon-CL-20 still remain unclear. We perform quantum based self-consistent charge density-functional tight binding molecular dynamics simulations; in Combination with the multiscale shock simulation technique; to reveal the events with four specified shock velocities (Us) of 8 to 11 km/s. We find that the temperature and pressure increases and that the volume reduction is, enhanced with increasing shock strength. The ring opening is observed to -trigger molecular decay at all four shock,conditions; while the sufficient NO2 fission is observed at Us = 8 and 9 km/s, and strongly inhibited at Us = 10 and 11 km/s. Moreover, the evolution of main chemical species, such as active intermediates, stable products, and clusters, is strongly dependent on the shock strength. NO, and H are dominant in the primary intermediates, responsible for weak and strong shock, respectively; CO2 and N-2, as well as water, ate the main stable products with a population gradation determined by the shock strength; and the bigger clusters with longer durations are found to be caused by the stronger shodc-and their fast dissociation mainly undergoes through the ring opening. Besides, it is found that epsilon-CL-20 possesses weak,anisotropy in the above-specified Us range. This work will enrich the knowledge of shocked energetic materials, in particular the important energetic materials.