Abstract: In order to overcome the disadvantages of LNG truck self-pressurized unloading process, such as complex process, low efficiency, long unloading operation time, large disturbance by environmental factors and so on, the natural gas pressurized unloading process was proposed. Using process simulation software, the calculation model of natural gas pressurized unloading process was established and was used to study the operation pressure, operation temperature and actual liquid level in LNG tank during the unloading process. Meantime the total operation time required and natural gas flow rate were calculated for unloading process. The results showed that the natural gas pressurized unloading process was feasible and simple. The unloading operation had the characteristic of much shorter operation time, higher efficiency, and less disturbance by environmental factors.