Laser shock processing (LSP) is a novel surface treatment technology which uses laser-induced shock wave to strengthen material surface. The magnitude of the surface residual stress and the depth of compressive residual stress are important indexes for the evaluation of LSP's effect. The finite element method (FEM) simulation is a valid means for predicting residual stress field distribution in the metal after LSP. The ABAQUS software is applied to simulate the laser shock processing of 6061-T6 aluminum alloy. It discusses how to deal with finite element model, material behavior, the loading of laser shock wave, solution time and so on during the FEM of LSP, and the distributions of residual stress field induced by shock wave are also analyzed. At last the effects of multiple LSP processes on the residual stress field were evaluated by using FEM.