Polyaspartic acid is a kind of artificial synthetic biomimetic water soluble high molecular polymer material, having the characteristics of no phosphorus, non-toxic, pollution-free and complete biodegradable, and is a kind of internationally recognized “Green Chemicals”. Having the structure characteristics of peptide bond and active group such as carboxyl group, polyaspartic acid has strong effects such as chelate, dispersion, and adsorption, etc. and also has a good compatibility. It is widely used as the fertilizer synergist, and the corrosion inhibitors in the water treatment fields such as industrial cooling circulating water, reverse osmosis water, back injection water in oil field, metal cutting fluid, and boiler and steam pipeline; It can also be used as dispersant in papermaking, printing and dyeing and washing industry and the daily chemical field.