The inorganic zinc silicate shop primer film-forming mechanism, ethyl silicate hydrolysis, modifying and preparation of bases were introduced.By ethyl silicate modification, the flexibility of inorganic zinc silicate shop primer was increased. Based on salt spray resistance testing, zinc phosphate, B - 004 ferrophosphorus powder and 5% zinc powder as anti-corrosive pigments were chose. By comparing the application property, salt spray resistance and storage stability, the dosage of polyvinyl butyral resin was determined. HX - 8800 and BYK - 420 was chose as antisettling agent, 1%CB was adjusted into the solvent system to control the drying time, and finally the formula was determined.The product could meet automatic spray line application, paint film could dry quickly, had excellent anti-corrosive property, matched with varieties of topcoat, and didnˊt affect welding and cutting.