This paper mainly introduces the background, improvement process, operation and energy consumption analysis of the low-pressure methane hydrogen process improvement project of the ethylene plant of a petrochemical company in China, and analyzes and evaluates the effect after the improvement. One methane hydrogen compressor is to be installed during this process improvement to recover and utilize the low-pressure methane hydrogen from cold separation system. The new compressor is used to boost the low-pressure methane hydrogen and send it to fuel gas pipe network, so as to improve the operation flexibility of the ethylene plant. It provides support for the subsequent lighter feedstock and reduces the energy consumption of the ethylene plant.