Abstract: Oil leak causes quality changes of circulating cooling water, which affect the performance of the corrosion and scale inhibitors in circulating water system. In this study, the results of ATMP, HEDP and other corrosion and scale inhibitors in the case of diesel leaking was observed. And by using ATMP and biological enzyme together, a good corrosion inhibition in the circulating cooling water is obtained. A conclusion can be drawn that diesel oil leak will diminish the effect of ATMP, HEDP and other corrosion inhibitor. The ATMP, lysozyme and laccase pharmaceutical compound can achieve good inhibition results in the circulating cooling water at diesel dosage of 80mg/L. When the concentration of ATMP, lysozyme and laccase is 10,30,40mg/L, respectively, good inhibition effect can be achieved. The corrosion rate of carbon steel can be controlled below 0.008 mm/a. The corrosion inhibition rate is up to 95%.