Study of propagation and evolution of nonlinear seismic wave in earth crust is of important practical significance. In this paper, evolutions of nonlinear seismic longitudinal wave and transverse wave in microstructured earth crust are simulated detailedly by using the finite difference method. The results indicate that nonlinear seismic longitudinal wave and transverse wave in microstructured earth crust may evolve into one solitary wave or two solitary waves or solitary wave train, or disappearance. The initial amplitude of seismic wave, dispersion coefficient and body force factor significantly influence the evolution process. Our results reveal the evolution law of nonlinear seismic wave in a microstructured earth crust, which will help to explain some special seismic wave phenomena in theory.