Aiming at the problem of shrinkage cavity in melt-cast charge of small caliber warhead with large length-diameter ratio, the charge technology was studied. The small caliber warhead with large length-diameter ratio was equivalent to the cylinder with large length-diameter ratio, and a casting charge technology with bottom-up sequential solidification was proposed, and the simulation calculation and charging verification were carried out. The verification results show that the method can effectively avoid the shrinkage cavity in the charge.