According to the technical requirements of a central tube submunition, the effect of foam frame material on the muzzle velocity of submunition is discussed. The gradient dispersion structure of submunition driven by dispersion charge was simulated and theoretically analyzed, and the theoretical calculation formula of the initial dispersion velocity of large-mass submunition was put forward. The gradient dispersion scheme of central tube shrapnel was designed, and two groups of ground experiments were carried out. The relative error between the measured initial dispersion velocity of submunition and the theoretical calculation result was 4.79%. The results show that the dispersion charge mode and high density foam rack can realize the function of uniform dispersion of central tube cluster ammunition, which is more reasonable than the traditional cluster ammunition, and is more beneficial to the dispersion overload protection of bullets.