The invention provides a water-based bi-component white primer. The water-based bi-component white primer comprises two components A and B, wherein the component A comprises the following components in parts by weight: 200-300 parts of water-based hydroxy acrylic resin, 1-4 parts of an in-tank fungicide, 10-25 parts of a wetting dispersant, 4-15 parts of a defoaming agent, 5-15 parts of a film-forming aid, 150-300 parts of wollastonite, 350-500 parts of fillings, 10-30 parts of a rheology controller, 5-10 parts of a base material wetting agent and 50-150 parts of water; the component B is a water-based polyisocyanate curing agent. The dually-curable water-based resin with high solid content and low hydroxyl value is utilized, is matched with the specific water-based polyisocyanate curing agent and is supplemented with the fillings including wollastonite and white barium powder to form a special thixotropic thickening system, so that the storage stability of products is improved, and the special thixotropic thickening system is excellent in construction performance, environmentally friendly and ultralow in VOC content and further has the characteristics of ultrahigh solid content, high drying speed and hardness, good collapse resistance, high crosslinking density, good solvent resistance and the like.