The invention relates to a modified water-based inorganic zinc rich coating and preparation thereof. The modified water-based inorganic zinc rich coating is produced by mixing a composite powder with a water-based inorganic binder in a weight ratio of (65-75): (35-25), wherein the composite powder comprises 40-70 parts of metal zinc powder, 3-15 parts of composite iron-titanium powder and 0-15 parts of an antirust agent; the water-based inorganic binder is a lithium silicate binder and comprises 10-25 parts of lithium silicate binder, 60-75 parts of silica sol, 10-15 parts of modified binder and 0.6-3 parts of other auxiliaries; and the modified binder is organic fluorine and / or an organic silicon modified acrylic emulsion. The water-based inorganic lithium silicate binder is used as the base stock of the modified water-based inorganic zinc rich coating, so that the coating is quick in air-drying, nontoxic, tasteless and non-combustible, and has excellent abrasive resistance, flexibility, impact resistance, bending resistance, high / low temperature resistance, electric welding resistance and chemical corrosion resistance, as well as high binding strength, resistance to heat and humidity, salt water resistance and long salt fog resistance time; therefore, the coating is suitable for various building steel structure as a heavy corrosion protective primer, and also can be used as a paint for closure of thermally sprayed zinc, thermally sprayed aluminium anticorrosion layers.