The work aims to explore the influence of dual shot peening parameters on the surface integrity of 42CrMo steel components. A 3D random shot peening (SP) finite element model (FEM) was established and the accuracy of predicting the residual stress by the model was verified by experimental data. The surface topography and stress-strain results of the component after single shot peening were imported into the dual shot peening model as the initial state, to construct the prediction model of dual shot peening. The effects of the dual shot peening parameters on the surface residual stress field, surface roughness and equivalent plastic deformation (PEEQ) field of 42CrMo steel components were analyzed. The compressive residual stress value near the surface layer (0~100 μm) of 42CrMo steel components after dual shot peening increased compared with the initial state, and the dual shot peening coverage ratio had the most obvious effect on the improvement of the surface residual stress, with the maximum increase of 63.3% compared with the initial state. On the contrary, the improvement effect of dual shot peening diameter on residual stress was the least obvious. The excessive increase of the dual shot peening speed would lead to the significant increase of the surface roughness while the increase of the dual shot peening coverage ratio could significantly reduce the surface roughness, and the roughness was 14.4% less than the initial state when the coverage ratio was 300%. The surface PEEQ value ascended with the increase of the dual shot peening speed, shot diameter and coverage ratio. However, when the shot speed, shot diameter and coverage ratio increased to a certain extent, the PEEQ value tended to be saturated. The prediction model of dual shot peening reveals the relationship between dual shot peening parameters and surface integrity of 42CrMo steel component, which provides some guidance for the industrial application of dual shot peening.