Abstract: With maleic anhydride（MA）,acrylic acid（AA） and hydroxyethyl methacrylate（HAMA） as the monomer,a novel terpolymer scale inhibitor was synthesized through aqueous radical polymerization,and the number average molecular weight of the copolymer around 1259 belonging to the distribution of narrow transition zone molecular weight. The copolymer was analyzed with infrared spectroscopy and scanning electron microscope（sem）,it containing carboxyl,amide and sulfonic acid functional groups which dispersed scale required,lattice distortion and complex solubilizing a major role in suppressing precipitation copolymer mechanism. Through the comparative test on the scale inhibition performance of terpolymer scale inhibitor and four common green scale inhibitors,the influences of copolymer dosage,mass concentration of calcium ions and water temperature on scale inhibition performance were discussed. The results showed that,when the copolymer dosage was 3mg/L,the water temperature was 80℃,the mass concentration of calcium ions was 480 mg/L,the scale inhibiting rate reached 91. 35%. The copolymerperformance of calcium carbonate scale superior to conventional inhibitors,especially appropriate for the industrial circulating cooling water with high temperature and high hardness.