The present invention relates to liquefied gas treatment system and method, and the liquefied gas treatment system includes: a liquefied gas supply line connected from a liquefied gas storing tank to a source of demand; a heat exchanger provided on the liquefied gas supply line between the source of demand and the liquefied gas storing tank, and configured to heat exchange liquefied gas supplied from the liquefied gas storing tank with heat transfer media; a media heater configured to heat the heat transfer media; a media circulation line connected from the media heater to the heat exchanger; a media state detecting sensor provided on the media circulation line, and configured to measure a state of the heat transfer media; and a controller configured to set a coagulation prevention reference value for preventing the heat transfer media from being coagulated, and change a flow rate of the heat transfer media flowing into the media heater or calories supplied to the heat transfer media by the media heater on the basis of a state value of the heat transfer media by the media state detecting sensor and the coagulation prevention reference value.