Abstract: The corrosion inhibition of a kind of green scale inhibitor, polyepoxysuccinic acid (PESA) was studied based on dynamic experiments. In addition, the synergistic effect among PESA, Zn²⁺ and sodium gluconate was also investigated. According to the experimental data, when only PESA is used, it had fairly good effect on steel. The synergy between PESA and Zn²⁺ or sodium gluconate was poor. However, the synergistic effect of PESA, Zn²⁺ and sodium gluconate is very good. Further experiments show that the corrosion inhibition of PESA is mainly affected by oxygen atom inserted.