In an ethylene plant with ethane and propane as the feedstock, the influence of different ratios of ethane feedstock on the distribution of cracking products was investigated while the total ethylene yield remained unchanged. The analysis shows that with the increase in ethane feedstock, hydrogen and recycle ethane remarkably increased while other components decreased to varying degrees. Based on this, the influence of different ratios of ethane feedstock on the cryogenic separation in ethylene plant is studied. The conventional adjustment methods for cryogenic separation system with different ratios of ethane feedstock are summarized, and the power consumption of cracking gas compressor, propylene compressor and ethylene compressor with different ratios of ethane feedstock is compared with each other through process simulation.