Abstract: To study the correlation between the centre high explosive charge for fuel dispersal and the scale of FAE device, the law of similitude in the fuel dispersal process has been set up with the dimension anlytic technique in this paper. The similarity criterions in the acceleration stage and the deceleration stage of the fuel dispersal process are put forward. This paper has provided the basis for the design of the centre high explosive charge in the FAE device. When the FAE device scale becomes biger, the comparative mass of centre high explosive charge and fuel should not been changed.