In the dispersal of fuel mixture,a key technique in fuel air explosive weapons,concentration distribution and volume of fuel cloud are the main factors of explosion effect of a fuel air explosive device. The fuel/air cloud volume and consistency can be controlled by center high explosive charge in a fuel air explosive device. Fuel/air cloud dispersal processes of four kinds of center high explosive charges were introduced in this paper. The experimental results show that the cloud dispersal velocity varies from high to low and tends to zero. When the cloud dispersal velocity drops to zero,the volume of cloud reaches max. The max cloud volume relates to center high explosive charge and increases with the total energy when the total energy of center high explosive is lower. When the total energy of center high explosive reaches a critical value the max volume of cloud does not increases with the total energy. The conclusion has offered a basis for improving the cloud dispersal characteristic feature and detonation effects of FAE.