An lubricating oil moisture monitoring system was designed based on ARM to solve the problem of cooling water pollution of the lubrication system for finishing mill of high speed wire rod.The EIS impedance spectrum sensor fwd-1 was adopted in the system,and the measured result of moisture content was compensated by temperature,which improves the measurement accuracy and stability.An isolated CAN bus network was designed to improve the reliability of network communication.The system of uCOSIII and emWin was adopted for the monitoring interface of the main control station.The simulation results show that the system can accurately detect the moisture content of lubricating oil and has good practical value.