Abstract:() : The cold end system of a thermal power plant plays the role of a cold source in the thermodynamic cycle. According to the Rankine cycle, reducing the final parameters of the unit is the main means to improve the cycle efficiency of the unit, reduce the energy consumption of the unit, and enhance the economic performance of the unit"s operation.The cold end system of the steam turbine consists of the condenser, the vacuum extraction system and the circulating water system (including the circulating water pump and the cooling tower). The quality of the operating conditions of the cold end system directly has a significant impact on important economic indicators such as the unit output, the unit heat rate, the unit auxiliary power consumption rate and the coal consumption for power supply.Strengthening the operation adjustment tests, maintenance and overhaul of the cold end equipment system of the steam turbine, as well as enhancing the operation management and maintenance of the equipment system to ensure that the vacuum tightness of the unit condenser remains within an excellent range for a long time is of great significance for improving the economic and safe operation of the unit.