Abstract: Gels decontamination technology is an advanced decontamination process of metal contaminated by radionuclide. Oxidizing gels have strong corrosion effects on stainless steels, so are acid gels on carbon steels and alkaline gels on aluminum. By spraying method, the experiment is focused on how the content of gels and contact time affect corrosion. The results show that the layers of stainless metals contaminated by radionuclide are stripped over 1 μm when the contents of oxidizing gels are limited to more than 0.6 kg/m² within 3-4 h; the layers of carbon steels are stripped over 3.5 μm when the contents of acid gels are limited to more than 0.4 kg/m² within 30 min; the layers of aluminum are stripped to the maximum of 35 μm when the contents of alkaline gels are limited to more than 0.5 kg/m² within 1 h, however, the corrosion depth is below zero when contact time is over 2 h.