As the core equipment of ethylene plant, quench water tower is mainly used to further reduce the temperature of cracking gas to near ambient temperature and achieve the separation of water, heavy aromatic hydrocarbons, and heavy tar. The continuous increase in packing pressure difference in quench water tower not only increases the energy consumption of cracking gas compressor, but also poses risks of tower internal collapse and tower flooding, which can lead to compressor interlock shutdown, severely restricting the long-term operation of ethylene plant. This article focuses on the problems of packing scaling and increased pressure difference in quench water tower. Online flushing is adopted for the lower packing to reduce the pressure difference from 8.0 kPa to 3.6 kPa. Reasons for packing scaling are analyzed, and reasonable measures are proposed to prevent the scaling in quench water tower.