Abstract: To further optimize the BOG treatment process in LNG terminals and reduce energy consumption of the entire LNG terminal, a LNG terminals with LNG output capacity of 200 t/h and BOG evaporation of 3.04 t/h is taken as an example to analyze power consumptions of two classical BOG treatment processes, namely re-condensation process and direct compression process. The results show that BOG compressors and high-pressure LNG pumps contribute dominant proportions in energy consumption. ASPEN-HYSYS simulation software is used to optimize existing processes. Specifically, LNG is further pressurized to a level higher than outlet pressure, and the gasification and expansion of the high-pressure outlet natural gas are used to compress BOG and pressurize LNG. The improved BOG direct compression process and re-condensation process can reduce energy consumption by 1 616.27 kW and 1 270.64 kW, respectively.