The work aims to optimize the finite element simulation technology of shot peening technology since limited shots are used by most models in finite element simulation of shot peening, randomness of shot position and the effects of shot peening coverage to residual stress field are not accurately reflected. By virtue of a large-scale finite element analysis software ABAQUS, python programming language was used to randomize the distribution of shots in three-dimensional space and finite element model of random multi-shot shot peening was established. Provided that coverage rate of shot peening exceeds 100%, effects of shot quantity, size and velocity of shot peening technology on residual stress field were analyzed and simulated, and the rationality of the finite element model was verified by experiment. Thickness of compressive residual stress layer and the maximum residual stress could be increased by adding shots. The residual stress field was nearly satured when there were 90 shots. As the shot velocity increased, the peak value of residual stress on target, surface stress value and the depth of residual stress field increased and the site where residual stress peak was present kept unchanged. As the shot diameter increased, peak value of residual stress on target, surface stress value and the depth of residual stress field increased significantly. The measurement results of shot peening residual stress test are consistent with that of finite element simulation and the finite element model is reasonable.