A method for preparing a graphene-containing inorganic coating composition for coating non-ferrous metal objects, the method comprising:
- adding isopropyl alcohol as a solvent to liquid silica sol and a liquid sealant, followed by uniform stirring for 2 to 3 hours, thereby preparing a first liquid binder;
- adding powdery graphene, a powdery filler and a powdery pigment to the first liquid binder, followed by stirring for 8 to 10 hours, thereby preparing a second binder;
- and
- adding a predetermined amount of an adhesion-enhancing agent to the second binder, followed by aging at a temperature of 25 to 32° C. for 9 to 11 hours.