One component waterborne iron red precoating primers are developed and applied with one component waterborne emulsion used as film-forming substance,iron oxide red and phosphate used as antirust pigment,filler and waterborne additives.The coatings have excellent anti-rust performance,rapid drying characteristics,meet the requirements of coating and welding,are in line with the standard specifications,are safe and environmentally friendly,have convenient construction,and have cost advantages.These coatings are suitable for rail transit,steel structure,container and other fields.