The utility model provides an ethane cryogen system that stores suitable for FLNG, supply jar and additional jar of liquid phase cryogen including ethane flash tank, ethane loading and unloading arm,ethane storage tank, ethane delivery pump, ethane vaporizer, refrigerant vapor, the ethane storage tank is connected respectively to ethane flash tank and ethane loading and unloading arm, the gas exports of ethane storage tank connects fuel gas system, and liquid ethane divides two the tunnel after the pressurization of ethane delivery pump, connect through the ethane vaporizer all the way refrigerant vapor supplyes the jar, and another way is connected the liquid phase cryogen supplyes the jar. The utility model discloses can realize that ethane utilizes entirely, gaseous phase ethane can regard as the fuel gas on the FLNG to use, and the liquid phase is used for the cryogen to supply. If the ethane quantity of output in the feed gas is greater than the ethane quantity that the cryogen supplyed, regular outer shipping and selling is sold to remaining ethane in the ethane storage tank, supply required ethane if the ethane quantity of output in the feed gas is less than the cryogen, itis required then need regularly to purchase the agent of ethane benefit refrigerant filling type.