Abstract: In order to improve the power efficiency of refrigeration circulating water system and reduce power consumption, after comparing the common used three-phase asynchronous induction motor with permanent magnet motor, and analyzing their energy consumption utilization rate under full load condition, the permanent magnet motor water pump which have high-efficiency, high-power factor is selected. Then, the transmission methods between the motor water pump and the fan, as well as between the motor and the water pump are optimized. Methods of the direct connection between the motor and fan blades, and the long coupling connection between the motor and the pump head are adopted respectively to achieve the effect of reducing fan power consumption and noise, and improving efficiency of the water pump head. Finally, the control mode of the entire system is optimized to achieve automatic closed-loop operation. By comparing the use effect and electricity consumption before and after the transformation, it is concluded that the energy consumption of the water pump is reduced by 29.6%, the energy consumption of fan is reduced by 90.7%, the actual monthly electricity consumption of the system is reduced by 33%, and the noise reduction effect of the fanis remarkable though this renovation.