The invention relates to a long-acting self-cleaned aqueous inorganic nano ceramic coating and a preparation method thereof. The ceramic coating consists of an aqueous self-cleaned inorganic nano ceramic emulsion, a pigment, a packing, a lubrication dispersant, a defoaming agent, a rheological agent, water and the like. The preparation method comprises the following steps: mixing one or multiple silanes with an organic silicon modifier and hydroxyl functional group organic silicon oligomer so as to obtain a transparent mixed silane liquid; putting silica sol and water into the transparent mixed silane liquid, and stirring, slowly heating, stirring at a constant temperature, leaving to stand, keeping the temperature, adding water, and cooling so as to obtain an aqueous self-cleaned inorganic nano ceramic emulsion; mixing the prepared aqueous self-cleaned inorganic nano ceramic emulsion with the pigment and the packing, and dispersing and grinding at a high speed; after grinding is completed, uniformly stirring with an aid and water, so as to obtain the long-acting self-cleaned aqueous inorganic nano ceramic coating. The coating product provided by the invention is a lyophobic anti-graffiti long-acting self-cleaned coating with excellent properties of high density, high hardness, good wearing resistance, super good weather resistance and integration from inside to outside.