Abstract: In view of problems of water wasting and environment pollution existed in industrial circulating water system, a polarizing control system of industrial circulating water based on ARM was designed. The system uses polarizing energy detection circuit to real-timely detect water quality parameters of circulating water, then the parameters are processed by STM32F103 to get PWM polarizing energy control signal which is integrated, isolated and amplified by polarizing energy output circuit to drive polarizing body, so as to produce polariaing field to act on circulating water. The actual application showed that the system can control circulating water system running at high concentration rate, which replaces dosing treatment process of circulating water system and reaches goals of reducing water consumption and preventing water pollution.