In order to further improve the corrosion resistance of S32750 super duplex stainless steel, the passivation treatment was carried out by nitric acid passivation. The corrosion resistance of S32750 super duplex stainless steel was investigated by electrochemical polarization curve, electrochemical impedance spectroscopy, Mott⁃Schottky curve and immersion method,and the corrosion surface morphology of the sample surface before and after corrosion was observed. The results show that the nitric acid passivation time has a significant effect on the corrosion resistance of S32750 super duplex stainless steel passivation film. When the passivation time is less than 120 minutes, the longer the passivation time, the smaller the corrosion rate is, and the better the passivation film corrosion resistance is.