A three dimensional finite element model is established to estimate the residual stress field induced by single laser shock processing (LSP) in aluminum alloy round rod part. The simulation results are consistent with the experimental results. The effect of laser parameters including laser power density, shock angle and shock times on residual stress field is systematically investigated with the aid of the established model. The results show that during the laser shocking of round rod, larger laser power density causes smaller compressive residual stress in the central spot area. The compressive residual stress in the center area turns into tensile residual stress with the increase of laser power density, and increases with the increasing shock angle. Moreover, the compressive residual stress at the spot center increases significantly under certain impact times and gradually reaches saturation. The plastically affected depth increases with the increase of laser power density and shock times, and is almost not affected by the shock angle.