Abstract: The invention relates to the technical field of nuclear reactor materials, in particular to a processing method for improving the corrosion resistance of iron and steel materials in lead or lead-bismuth, comprising the following steps: selecting iron and steel materials containing Mn and Cr elements, using high-energy fast neutrons generated by fission as the radiation source, and performing irradiation on the iron and steel material so that Mn and Cr elements diffuse to the surface of the iron and steel material to form a dense oxide film, so as to complete the improvement of the corrosion resistance of the iron and steel material. The invention enhances the formation of the dense-structured oxide layer by irradiation. The oxide layer has good protection and self-healing properties in irradiation environment, and a new solution is proposed for enhancing the corrosion resistance of steel in lead and lead-bismuth coolant fast reactors.