Abstract: Yibin Data light hydrocarbons recycle project deals with gas from shallow oil and gas field to recycle light hydrocarbons, liquefied petroleum gas (LPG) and produce liquefied natural gas (LNG) in Data, Yibin. According to the gas components of oil and gas field and characteristics of the project, the direct heat exchange (DHX) technology is adopted to recycle light hydrocarbons and single cycle compound throttling mixed refrigerant-cycle refrigeration (SMCR) is used for natural gas liquefaction. The output pressure of natural gas pipeline network had been set, so the operating parameters of the process need to be optimized. HYSYS was applied to simulate, optimize and calculate the recovery of light hydrocarbons and process of LNG liquefaction. This article analyzed DHX process under different temperatures to optimize operating parameters on the basis of energy consumption, recovery rate and economic benefits.