The invention discloses a device and a method for preparing oxygen by vacuum pressure swing adsorption (VPSA) through five towers. The device comprises two blowers, two vacuum pumps, five adsorption towers, two equalizer tanks and an oxygen buffer tank, wherein the inlets of the five adsorption towers are connected together, and are connected to the two blowers and the two vacuum pumps; the outlets of the five adsorption towers are connected together, and are connected to the oxygen buffer tank; the five adsorption towers are connected with the two equalizer tanks respectively through pipelines. By adopting the technical scheme of the invention, the oxygen yield can be increased, and the defects of low oxygen utilization ratio, low adsorbent utilization ratio and high equipment manufacturing cost in the conventional vacuum pressure swing adsorption oxygen production process are overcome.