The utility model provides a liquefied natural gas adorns unloading system, the system includes that LNG loading house steward, LNG loading pipeline, BOG return arm, BOG return -air pipeline, BOG return -air house steward, LNG unload pipeline, LNG unload house steward, high -pressure natural gas admit air pipeline and high -pressure natural gas inlet manifold. When unloading, open the hand valve who is located loading and unloading car arm, utilize LNG precooling loading and unloading car arm on the tank wagon, the hand valve who is located BOG and returns the arm is opened after accomplishingto the precooling, can utilize high -pressure natural gas to carry out the pressure boost to the tank wagon, uninstalls LNG on the tank wagon to the LNG storage tank. Because the utility model discloses a high -pressure natural gas pressure boost is unloaded, and operation flow is simple, only needs to accomplish the precooling of loading and unloading car arm, and the precooling time is short, has improved unloading efficiency, and it is less influenced by ambient temperature, also can accomplish smoothly when ambient temperature is lower and unload, has overcome the shortcoming from booster-type unloading system environmental suitability is poor.