Potassium silicate for inorganic coatings is a stabilized potassium silicate obtained by a series of nano-modifications on high-purity potassium silicate. A first-generation product, especially suitable for making silicate inorganic architectural coatings. By compounding with a small amount of polymer emulsion, it can be used for the inner and outer walls of buildings, and can effectively penetrate into the concrete wall and form an integral body with the cement surface. This kind of coating has excellent fire resistance, air permeability, mildew resistance, weather resistance and so on. It can also be used as a surface hardening treatment agent for cement concrete substrates or diatom mud, which can effectively seal and resist efflorescence and surface hardening to prevent powder drop.