Modern ethylene plant has the characteristics of large system, long process flow, severe process conditions and numerous critical equipment, which make it difficult to store materials during startup and shutdown of the plant, and a large amount of material discharged will cause environmental pollution. By analyzing the characteristics of technologies for low emission startup and shutdown of three kinds of unit layout including two ethylene plants, a single ethylene plant with recovery system and a single ethylene plant, this paper presents the optimal solution to achieve the low emission startup and shutdown of the plant, so as to reduce the material emission and minimize the adverse impact on the environment.