Taking the start-up and shutdown processes of the 220 t/a ethylene plant of a petrochemical company for overhaul in 2024 as the research object, this paper systematically analyzes the application effect of technical measures for start-up and shutdown. Through optimization measures such as discharging materials from each cracking furnace one by one, reheating the cryogenic separation zone, and putting the shut-down material recovery line into operation, all suitable materials have been recovered, and the emission reduction control of the ethylene plant has reached the best level in history. It has effectively reduced the material loss during start-up and shutdown, and improved the energy utilization efficiency. Meanwhile, this paper conducts a systematic analysis of the equipment problems and operational deficiencies exposed during the start-up and shutdown, and puts forward some improvement suggestions.