According to observation results of explosive dispersion process of FAE (fuel-air explosive) test device with fast kinematics analysis system, the different dispersion stages of fuel were characterized and the influence of specific central explosive, ratio of height to diameter and shell material to fuel dispersion was studied in this paper. The results show that dispersion process can be divided into the following three phases, jet formation and expansion movement phase, two-direction expansion movement phase and gas-liquid amalgamation movement phase. The different stages of fuel dispersion process correspond with different hydrodynamics characteristics and contribute to the formation of cloud in respective. Under the conditions of general optimization of test device, cloud area and volume were expanded by properly increasing specific central explosive. The ratio of height to diameter was not a remarkable factor influencing cloud status, but larger ratio of height to diameter dispersed fuel better. Cloud dispersion of steel shell was better than that of aluminum shell. It is concluded that ideal detonation status of cloud and high power effect can be attained when the steel shell, specific central explosive about 3% and ratio of height to diameter between 3 and 5 are adopted and are well-matched of three device parameters above.