Abstract: To achieve energy conservation and operational efficiency improvement, an optimized design of variable frequency control was implemented for the clean water pump system at a municipal water plant in Guangdong. The research results show that the overall energy consumption of the system has been reduced by about 43% after energy-saving optimization, and improve water supply stability by 23%, the pressure fluctuation of the pipeline network has been reduced from ±5% to ±3.7%, the optimization of the temperature control system in the pump room has improved the operating environment of the equipment, the number of system starts and stops has been reduced from 15 times per day to 3 times. It can be seen that the optimized design of frequency conversion control in this project has significantly improved the energy-saving effect and system operation efficiency of the water plant.