Abstract: A method is provided for purifying and recycling water vapor from a coal drying process and device which employ temperature reduction and dehumidifying, a flash distillation, and vacuum condensation. With a condensed tower, a high humidity exhaust gas is preliminarily lowered in temperature, and condensed water of 5˜60° C. is pumped, are received, vapor-liquid reverse contact is performed, and temperature reduction and dehumidifying occurs. With a flash distillation tank and a demisting washer, condensed water of 40˜100° C. pumped by the flash distillation water pump is performed on vacuum flash distillation, water vapor of 5˜60° C. evaporated in the flash distillation tank enters into the demisting washer to be dehumidified and then into a vapor condenser. With a condenser and a water ring vacuum pump, water vapor of 5˜60° C. is condensed through mist eliminating and washing by the demisting washer, condensed water is recycled, and non-condensable gas is discharged.