The isothermal oxidation behavior of GH3535 alloy before and after shot peening at 900 °C was investigated by using discontinuous increasing weight method. The results show that the samples of Weight gain of the 0.45 Nmm shot peening strength was reduced by 79.7% compared to the unshot sample at 900℃. The main oxide products of unshot GH3535 alloy are NiCr2O4，MoO2，NiMoO4； While the surface oxide film products of GH3535 alloy is composed of NiO, NiFe2O4, Cr2O3 and NiCr2O4 after shot peening treatments. Plastic deformation was performed on the surface of GH3535 alloy and refined the grains due to shot peening The main reason for the increase of Cr atom diffusion flux is that the dislocations and grain boundaries of the plastic deformation zone of the alloy surface act as a fast diffusion path of Cr atoms, and the Cr2O3 layer is more quickly formed, which promotes the diffusion of Cr to the surface to form Cr-rich oxides, and reduce the transient oxidation period