Pollution of cooling water in lubrication system is the most common problem in high speed wire rod production line.A electrochemical impedance spectroscopy(EIS)device was used to realize the realtime water monitoring in highspeed wire mill lubricating system.The design of installation location of EIS water content sensor was introduced.The onsite testing results show that the sensor can accurately detect whether water leaks into the lubricating system and determine the amount of water leaked.The sensor is proved to be able to provide the realtime trend curve of the water content and effective alarm,and the abnormal wear,damage or burning of rolling friction fairs can be prevented.