This paper uses LS-DYNA finite element analysis software and is based on JPC water penetration tests to investigate the effect of liner parameters (wall thickness, material), charge aspect ratio on the movement characteristics of JPC in water. It has been shown that the head diameter of the JPC becomes larger and produces mass erosion after entering the water, and there are two phases in the effective length of the JPC in the water, including the growth phase and the decrease phase, and the velocity of the JPC decays exponentially. Increasing the thickness of the liner and the charge aspect ratio will improve the erosion resistance and the velocity storage capacity of the JPC. The optimum range of values for the thickness of liner is in the ranges of 0.036D_k to 0.055 D_k. After a charge aspect ratio higher than 1.25, the charge structure has less effect on the movement characteristics of the JPC in water. The density of the material has an important influence on the velocity decay pattern of the JPC during water penetration, The ability of a JPC with a high density to store velocity in water, with the velocity decay pattern converging if the densities are similar. The higher density of the JPC has the greater the ability to store velocity in water, and if the densities are similar the velocity decay pattern tends to be the uniform. The copper, tantalum and tungsten liners are suitable for use in the underwater shaped charge warhead.