In this study, the gradient grain induced by punching deformation and recovery treatment on a cupronickel alloy surface sample were investigated, and their effects on corrosion resistance were measured by atom force microscopy (AFM), X-ray diffraction (XRD), electrochemical measurement, electron work function (EWF), and contact electrical resistance (CER). The cupronickel alloy surface experienced punching deformation for 60 min and recovery at 300 °C for 1 h to produce gradient surface. The grain size measured by XRD is bigger than that measured by AFM, due to X-ray intensity of 95 % produced at the depth of 12–20 μm for the crystal planes of (111), (200), and (220). The gradient grain surface, compared to the original surface, shows a 13.7-fold decrease in passivation current density (ip), and corrosion potential (EC) increases by approximately 9.8 %. These results are attributable to the increase in EWF and formation of passivation film with better adhesion and compactness after treatment.