The invention relates to an all-in-one water-borne inorganic-organic hybrid architectural coating and a preparation method thereof, wherein the all-in-one water-borne inorganic-organic hybrid architectural coating is prepared by taking a compounded product of a water-borne inorganic film-forming matter and an organic polymer emulsion as a base material through the steps of adding various pigments / fillers and auxiliaries into the base material, then carrying out beating, grinding and paint mixing on the obtained mixture. In the invention, through a Si-O-Si polymer net structure which can be formed by compounding alkali metal silicates and small-particle-size silica sols in the process of film forming, the early water resistance of a paint film is greatly increased, and the eventual hardness, scraping resistance and stain resistance of the paint film are greatly increased; and through adding the organic polymer emulsion, the film-forming performance of the coating can be improved, and the defects that the traditional two-component inorganic coating is easy to crack, bad in decorative properties, poor in storage stability, and the like are overcome. The coating prepared by using the method disclosed by the invention has various functions of environmental friendliness, non-toxicity, thermal insulation, ultra scrubbing resistance, abrasion resistance, yellowing resistance, ageing resistance, fouling resistance, good air permeability, sound insulation, and the like.