The evaporative cooling system comprises: evaporative cooling modules, a liquid supply system which comprises a liquid supply pump and a tube, and which supplies a refrigerant liquid to the evaporative cooling modules; an air supply system which comprises air supply tubes, and which supplies warm air to the evaporative cooling modules; an exhaust system which comprises an exhaust pump and a tube, and which exhausts air containing a refrigerant vapor from the evaporative cooling modules; a reflux system which comprises a primary heat exchanger and a reflux tube, and which condenses the refrigerant vapor to return the condensed refrigerant liquid to the liquid supply system; and a heat exhaust system which comprises a secondary heat exchanger and tubes, and which discharges heat absorbed from the primary heat exchanger.