In recent years, due to the reduction of the amount of raw material gas and the change of equipment parameters, the liquefied natural gas recovery rate is reduced. According to the existing problems, the system needs to be optimized to improve the quality of the recovered liquefied natural gas. The HYSYS software was used to simulate the fractionation process. Through research, a parameter optimization scheme is proposed. Preferably, the initial stream inlet temperature, the deethanizer bottom temperature, and the depropanizer column top reflux rate are optimized for the original process flow to improve the liquefied natural gas recovery quality and reduce the equipment energy consumption. (C) 2018 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.