Abstract: A new type of drainage device selected for the gland steam condenser in a domestic new-built power generation unit was introduced, detail analyses were conducted on its composition, structure, and working principle, while comparisons were carried out between this device and the traditional gland steam condenser (adopting multistage water sealing). It is concluded that this device has the advantages of simpler equipment operation, stronger adaptability to back pressure, higher safety of the equipment itself and the unit, as well as being beneficial for the operation of air-cooled condenser units and peak regulation units. Based on above researches, a further energy-saving retrofit scheme of "zero leakage" of gland steam condenser was proposed. By optimizing the interface position with changing the installation height of internal pipelines, it is estimated to save an annual cost of 3 600 yuan in desalinated water production for the power plant.