The invention relates to a method for separating acetic acid and water, mainly solving the problems in the prior art that the energy consumption is high in acetic acid dehydrating process and equipment manufacturing cost is high. The technical scheme of the method is as follows: rectifying and dehydrating by adding pressure to an acetic acid dehydrating tower; using water as a heat-transfer medium during a heat pump cycle; absorbing heat released from condensation on materials discharged from the acetic acid dehydrating tower top by the heat-transfer medium in a closed heat pump flow; compressing the heat-transfer medium having absorbed the energy of the materials discharged from the tower top by a compressing machine, wherein the temperature of the medium is raised then; desuperheating the high temperature superheated steam by a desuperheating device to form saturated steam, and filling the steam in a tower kettle reboiler to exchange heat with the discharged materials from the tower bottom. The method with the above technical scheme better solves the problems in the prior art, and can be applied in industrial production for separating acetic acid and water.