A method for vacuum oxygen removal from water supplied to boiler includes such technological steps as spraying the water to be deoxidized by nozzle in vacuum deaerator to form jet beam, reducing pressure and expanding volume during spray to escape out dissolved oxygen, flushing the deaerated water in the state of jet into pressure-increasing pipe connected to output of vacuum deaerator to raise its pressure and generate enough cavitation allowance, and pumping it into boiler. The oxygen-containing steam goes through demoistening heat exchanger, where most of steam is condensed into water and further deaerated by deaerating heater. The rest of oxygen-containing steam is exhausted. Its advantages are simple structure, low-position arrangement and no need of high-flow spray suction pump.