A method of inhibiting metal corrosion is applicable to a metal-containing substrate, which has a surface in contact with a reaction solution. The method includes the steps of mixing ozone with the reaction solution and forming a metal oxide protective layer on the surface of the metal-containing substrate, so as to prevent metal beneath the protective layer from being continuously oxidized and corroded. In the method, the reaction solution contacting with metal is further adjusted in its oxidation-reduction property and pH value to change the corrosivity of the reaction solution and mitigate the corrosion tendency of metal.