The invention discloses a mildew-proof antibacterial inorganic coating which comprises water, cellulose, a dispersing agent, a wetting agent, a defoaming agent, titanium dioxide, mesh calcium powder, calcium powder, an inorganic emulsion, an inorganic anti-settling agent, silicate, an inorganic auxiliary agent, a mildew-proof agent, potassium silicate, silica sol, potassium oxide, lithium oxide, zinc oxide, calcium oxide, lead oxide, magnesium oxide, phosphate and a thickening agent. The mildew-proof effect can be effectively improved mainly by preparing the mildew-proof agent, meanwhile, in a humid environment, through a byproduct potassium carbonate generated by reaction of added potassium silicate, carbonate of a wall body and carbon dioxide in air, the coating can present strong alkalinity, can also play a lasting mildew-proof role in the humid environment, and is convenient and practical; the inorganic auxiliary agent is formed by mixing the quaternary ammonium salt stabilizer, the poly-tertiary amine stabilizer and the organic and inorganic silicide, and the quaternary ammonium salt stabilizer, the poly-tertiary amine stabilizer and the organic and inorganic silicide are mixed, so that a relatively good synergistic effect is achieved, and the stability is improved.