In order to investigate the influence of different laser shot peening (LSP) parameters on the strengthening effect, the finite element software ANSYS integrated with ISIGHT was adopted to establish a LSP parameterized file. Multi-island genetic algorithm (MIGA) was applied to optimize the process parameters of LSP, and an optimal parameter combination was obtained. The effects of different LSP parameters on the residual stress field and plastic deformation of the treated surface were discussed. Good consistency can be found between the simulation and experimental results under the optimal process parameters, which indicated that the optimization approach was feasible, and some guidance for the future research was also pointed out.