In order to investigate the creep performance of multi-barrel rocket weapon launch canister under long-term storage, uniaxial tensile creep test was carried out on composite laminate and the creep constitutive model parameters of single layer in the main directions were obtained. The finite element method and the user-defined material subroutine were used to establish long-term storage numerical analysis model of launch canister. Creep deformation of the bottom launch canister after 15 years storage was predicted. Taking the stored launch canister as initial state, the dynamic simulation model of rocket-tube coupling was built, and the influence of creep on rocket launching process was further investigated. Simulation results show that the change of the parallelism of the director and the flatness of the bottom surface of launch canister caused by creep are smaller than the specified values of technical indicators. The maximum residual deformation of director bundle is saddle-shaped in three-dimensional space, and the deformations of the middle position directors for upper and lower rows are largest, while that of the middle position directors for left and right columns are smallest. Creep deformation of the director reduces the clearance between rocket and director, increases the dynamic contact collision force and lessens the off-track velocity of rocket.