Aluminum alloy 2A02 is shocked by using the NdYAG laser with 1064 nm output wavelength and 20 ns pulse width. The surface hardness and residual stress of sample are measured, and the sub-structure of grain and its evolution behavior induced by laser shock are analyzed via the inverse fast Fourier transform (IFFT) method. The experimental results indicate that the surface hardness of the laser-shocked material increases by 50%, and the residual compressive stress of the laser-shocked test material reaches above 120 MPa. The transmission electron microscopy (TEM) and IFFT analysis of microstructure demonstrate that there are different types of dislocation configurations in the laser shocked area, mainly including edge dislocations and central dislocation bands; and the dislocation walls refine the original grain. The dislocation dipole close-array becomes the characteristic element of the nanocrystalline under the non-equilibrium deformation condition endowed by laser shock. Therefore, the complex dislocation configurations and the crystal lattice distortion induced by laser shocking are important to the improvement of surface hardness and residual stress.