In order to properly deal with the problem of excessive BOG caused by heating of LNG tank during the actual operation of LNG dual-fuel container ships, which endangers the operation safety of ships, and ensure the navigation safety of ships, based on the existing technology and project design, the causes of BOG caused by LNG bunker are analyzed. An effective BOG processing system design scheme and FGSS control system regulation logic are put forward, which provides suggestions and ideas for the design of LNG dual-fuel powered ships.