According to the characteristics and technical requirements of ammunition transportation, proposes a double-layer vibration isolation system with large load, establishes its dynamic model, solves the transfer function by using Laplace transform, analyzes the influence characteristics of various parameters on the transfer function through MATLAB, establishes the finite element simulation model and compares with the theoretical model, and verifies the accuracy of the model. On this basis, the corresponding optimization rules are set, and the NSGA-II optimization algorithm is used to optimize the system parameters, and the optimal parameters of the double-layer vibration isolator are obtained. Finally, the actual data are used to verify the vibration isolation effect. The results show that the vibration isolation effect of the double-layer vibration isolation system with large load is greatly improved compared with the single-layer linear vibration isolation system.