The work aims to take the plastics ammunition package as the object to study its dynamic characteristics. The simulation model of the package was established and the Finite element method was used to analyze the inherent characteristic of the structure. By considering the effect of random excitation on the missile in transit, the vibration damping effect of the package was studied under the vibration environment of the combined wheel vehicle. According to the transport test, the rationality of the simulation results was verified. The first six order natural frequencies of the box were distributed in the range of 53~81 Hz. Under the vibration environment of combined wheeled vehicles, the maximum stresses of the box in every direction were 192.4, 118.4 and 260.1 MPa, respectively; and the stresses and displacements on the projectile support and rubber cushion were very small. The package has better vibration damping effect under the random loads. The maximum stress of the structure is less than the yield limit of the material. Moreover, the finite element analysis results are reasonable and reliable, and the packaging box satisfies the design requirement.