Finite element simulation and experimental study on residual stress distribution of the 2024 aluminum alloy induced by flat-top laser shock are reported. Pressure distribution model of shock wave induced by flat-top laser beam is improved and applied to finite element simulation of residual stress field. High-quality flat-top laser beams, which are suitable for laser shock processing (LSP), are aquired and used for experiments of laser shock processing of 2024 aluminum alloy. The experimental results are consistent with the simulation results. The results show that the characteristics of flat-top laser beam shock processing of 2024 aluminum alloy can be concluded as follows. Residual stress distribution is almost even in the surface of impacted area of 2024 aluminum alloy when shock wave pressure is below a certain level; and once it exceeds this level, shock wave will produce residual stress hole, however, the distribution style is nearly equal. The results in the depth direction indicate that the impacted depth and the depth of maximum residual stress increase with laser shock pressure increasing.