The invention relates to the field of ships, in particular to a liquefied natural gas supplying system. The liquefied natural gas supplying system comprises a storage tank and a gas heater, wherein the storage tank is used for storing liquefied natural gas and evaporation gas of the liquefied natural gas; a gas inlet of the gas heater is connected with a gas outlet of the storage tank; a gas outlet of the gas heater is used for being connected with a gas supplying opening of a ship engine; the gas heater is used for receiving the evaporation gas in the storage tank and heating the evaporationgas to a preset temperature, and then the heated evaporation gas is input into the ship engine through the gas supplying opening of the ship engine. The gas heater can heat the evaporation gas of theliquefied natural gas in the storage tank to the preset temperature, then the heated evaporation gas is input into the ship engine through the gas supplying opening of the ship engine, and the gas isprovided for the ship engine. The change amplitude of pressure in the storage tank can be lowered, and compared with an existing gas supply mode of gasifying the liquefied natural gas, the liquefied natural gas supplying system is advantageous in that the gas supply stability can be improved.