During the switching of cracking gas dryer in the 220 kt/a ethylene plant of a petrochemical company, sometimes the cracking gas compressor may experience fluctuations in suction drum pressure and cracking gas flow, disrupting the inter-stage pressure balance. This may lead to fluctuations in the bearing temperature, vibration, and displacement of the cracking gas compressor, significantly impacting the long-term operation of the cracking gas compressor and the safe and smooth production of the entire plant. This article analyzes the causes of the above problems, and proposes some solutions to ensure the stable operation of the plant.