Abstract: With the increase of concentration multiple of circulating cooling water, the scaling of heat exchange equipment will aggravate. At the same time, the selection of scale inhibitors and descaling methods is severely restricted by the amount of circulating cooling water and blowdown of industrial scale circulating cooling water systems. Scale inhibitors are divided into three categories: traditional chemical scale inhibitors, green scale inhibitors based on petrochemical products and green scale inhibitors based on biological extracts. In this paper, the type and characteristic of scale inhibitors are analyzed and summarized, and the research status and development trends of scale inhibitors are introduced. Common physical descaling methods and research progress are briefly described, which the scale inhibition ability is relatively low and is easy to cause damage to the equipment. Some studies show that physical methods can significantly affect the performance of scale inhibitors when scale inhibitor are used in combination with physical methods. Combined with the current research situation of descaling in circulating water system, the development of descaling technology is summarized and prospected, and the suggestions for the use of scale inhibitors and descaling methods and new ideas for solving the scaling problems are put forward.