With the rapid development of industrial production, industrial water account for a very large proportion, and the amount of the cooling water also increases. It is likely to result in circulating cooling water system to produce a variety of problems. For that, we must add corrosion inhibitor, scale inhibitor and biocide to the circulating water system in order to ensure stability of the system.The application of Tolyltriazole will achieve greater results with the development of technology.