Based on the idea of MPI (Message Passing Interface) and the domain decomposition, a paralleled numerical model is developed for the simulation of gravity wave's nonlinear propagation. The model is based on the staggered grid system. The domain decomposition technique and data communication between each sub-domain in the staggered grid system are also presented in detail in the paper. The numerical simulation results for the propagation of gravity wave with small amplitude indicate that, the parallel numerical model can reproduce the propagation of small amplitude gravity wave and preserve the energy conservation relation. The parallel efficiency is about 0.65 and can be approximate to its maximum of 1.0 under the perfect conditions. As the comparison with the sequence model, the nonlinear propagation of gravity wave with finite amplitude was simulated by using the sequence and parallel model with different resolutions and the same computational time. The results indicate that, the parallel model can resolve the Kelvin-Helmholtz billows which appear after the time when gravity wave overturns and before the time when the turbulence is excited due to its relative higher resolutions and more processes. But, the sequence model can't resolve the fine phenomena due to its lower resolutions in the same computational time.