The invention discloses a low-pressure ethanol recovery device and method with triple effect rectification. The low-pressure ethanol recovery device with triple effect rectification comprises a first rectifying tower, a second rectifying tower, a third rectifying tower, a rectifying tower reboiler, a rectifying tower feed preheater, a condenser, a return tank, a dilute ethanol feed preheater, a temporary finished product storage tank and a finished product cooler. In the ethanol recovery method with triple effect rectification, by controlling the recovery of the finished ethanol in the second rectifying tower, the content of ethanol in tower bottom wastewater of the second rectifying tower is 5wt%-30wt%, the temperature of the tower bottom wastewater is 100-120 DEG C, and the working pressure of the third rectifying tower is 250-400kPa. The invention adopts the low-pressure triple effect rectification technique and reduces energy loss in the technical process, thus greatly reducing the energy consumption; and the operating pressure and temperature of the third rectifying tower are greatly reduced, and the requirements on the high temperature resistant and corrosion resistant properties of equipment are reduced, thereby reducing the equipment investment and the maintenance cost.