The utility model discloses a marine LNG fuel low pressure gas supply system of high redundancy mainly includes LNG fuel compartment, LNG vaporizer, LNG pump, combustion heater, fuel buffer tank to and relevant pipeline and remote -controlled valve. The utility model discloses LNG pump and vaporizer combine together, fully provided different work condition air feed demand down, and the air feed is stablized in the realization under abominable operating mode of guarantee boats and ships to through the process flow design of optimizing, with the LNG vaporizer of two different functions realizing can also being reserve mutually under the prerequisite of self function of tonic chord, fully guarantee the redundancy of fuel compartment pressure boost, air feed, guaranteed the stability of air feed.