Abstract: Condensate polishing plays an important role in ensuring the water and steam quality of the unit. According to statistics, the supercritical unit is mainly in the form of pre-filtration+mixed bed, and the sub-critical unit and below are mainly in the form of mixed bed, mainly in the form of high tower regeneration. Through the chemical technical supervision and research of the power plant, it is found that there are some problems such as the operation bias of the mixed bed, resin leakage and poor regeneration effect in the polishing treatment at present. On the basis of the existing improved technology, combined with the on-site analysis and treatment of the condensate polishing problem, further optimization technology is proposed from the design and operation, which can effectively prevent the damage of the water distribution device of the mixed bed, resin leakage and ensure the resin regeneration effect, thus improving the operation cycle of the mixed bed, reducing the amount of demineralized water and wastewater discharge. At the same time, it also discusses the operation mode of water saving and emission reduction in the polishing treatment, which is conducive to the implementation of the zero discharge project of power plant wastewater, and has obvious economic and environmental benefits.